Fixes the following GCC 5 warnings:
```
core/io/zip_io.h:128:26: warning: 'zlib_filefunc_def zipio_create_io_from_file(FileAccess**)' defined but not used [-Wunused-function]
core/script_debugger_remote.cpp:110:17: warning: 'ObjectID safe_get_instance_id(const Variant&)' defined but not used [-Wunused-function]
drivers/unix/socket_helpers.h:103:12: warning: 'int _socket_create(IP::Type&, int, int)' defined but not used [-Wunused-function]
drivers/unix/socket_helpers.h:45:15: warning: 'size_t _set_sockaddr(sockaddr_storage*, const IP_Address&, int, IP::Type)' defined but not used [-Wunused-function]
drivers/unix/socket_helpers.h:76:15: warning: 'size_t _set_listen_sockaddr(sockaddr_storage*, int, IP::Type, IP_Address)' defined but not used [-Wunused-function]
editor/editor_fonts.cpp:40:24: warning: 'Ref<BitmapFont> make_font(int, int, int, int, const int*, const Ref<Texture>&)' defined but not used [-Wunused-function]
editor/editor_themes.cpp:85:26: warning: 'Ref<StyleBoxFlat> change_border_color(Ref<StyleBoxFlat>, Color)' defined but not used [-Wunused-function]
editor/import/editor_import_collada.cpp:493:13: warning: 'void _generate_normals(const PoolVector<int>&, const PoolVector<Vector3>&, PoolVector<Vector3>&)' defined but not used [-Wunused-function]
editor/import/editor_import_collada.cpp:524:13: warning: 'void _generate_tangents_and_binormals(const PoolVector<int>&, const PoolVector<Vector3>&, const PoolVector<Vector3>&, const PoolVector<Vector3>&, PoolVector<float>&)' defined but not used [-Wunused-function]
editor/pvrtc_compress.cpp:118:13: warning: 'void _compress_etc(Image*)' defined but not used [-Wunused-function]
modules/etc/image_etc.cpp:89:13: warning: 'void _decompress_etc1(Image*)' defined but not used [-Wunused-function]
modules/etc/image_etc.cpp:93:13: warning: 'void _decompress_etc2(Image*)' defined but not used [-Wunused-function]
modules/gdscript/editor/gdscript_highlighter.cpp:46:13: warning: 'bool _is_whitespace(CharType)' defined but not used [-Wunused-function]
scene/2d/cpu_particles_2d.cpp:510:14: warning: 'float rand_from_seed_m1_p1(uint32_t&)' defined but not used [-Wunused-function]
scene/3d/cpu_particles.cpp:474:14: warning: 'float rand_from_seed_m1_p1(uint32_t&)' defined but not used [-Wunused-function]
scene/resources/default_theme/default_theme.cpp:123:20: warning: 'Ref<Shader> make_shader(const char*, const char*, const char*)' defined but not used [-Wunused-function]
scene/resources/default_theme/default_theme.cpp:130:24: warning: 'Ref<BitmapFont> make_font(int, int, int, int, const int*, const Ref<Texture>&)' defined but not used [-Wunused-function]
```
Had to split `core/io/zip_io.h` into header and .cpp file without 'static' keyword.
Not fixed yet (static definition in header used in some files but not all):
```
modules/websocket/lws_helper.h:111:13: warning: 'void _lws_make_protocols(void*, int (*)(lws*, lws_callback_reasons, void*, void*, size_t), PoolVector<String>, _LWSRef**)' defined but not used [-Wunused-function]
```
Also fixed a couple other warnings missed in previous commits.
Fixes the following GCC 5 warnings:
```
core/object.h:193:11: warning: 'MethodInfo::flags' will be initialized after [-Wreorder]
core/object.h:192:15: warning: 'PropertyInfo MethodInfo::return_val' [-Wreorder]
core/object.cpp:278:1: warning: when initialized here [-Wreorder]
core/script_debugger_remote.h:97:6: warning: 'ScriptDebuggerRemote::max_cps' will be initialized after [-Wreorder]
core/script_debugger_remote.h:91:6: warning: 'int ScriptDebuggerRemote::max_messages_per_frame' [-Wreorder]
core/script_debugger_remote.cpp:1086:1: warning: when initialized here [-Wreorder]
core/script_debugger_remote.h:98:6: warning: 'ScriptDebuggerRemote::char_count' will be initialized after [-Wreorder]
core/script_debugger_remote.h:92:6: warning: 'int ScriptDebuggerRemote::n_messages_dropped' [-Wreorder]
core/script_debugger_remote.cpp:1086:1: warning: when initialized here [-Wreorder]
modules/bullet/area_bullet.h:102:7: warning: 'AreaBullet::isScratched' will be initialized after [-Wreorder]
modules/bullet/area_bullet.h:92:39: warning: 'PhysicsServer::AreaSpaceOverrideMode AreaBullet::spOv_mode' [-Wreorder]
modules/bullet/area_bullet.cpp:46:1: warning: when initialized here [-Wreorder]
modules/bullet/collision_object_bullet.h:127:15: warning: 'CollisionObjectBullet::space' will be initialized after [-Wreorder]
modules/bullet/collision_object_bullet.h:117:7: warning: 'CollisionObjectBullet::Type CollisionObjectBullet::type' [-Wreorder]
modules/bullet/collision_object_bullet.cpp:67:1: warning: when initialized here [-Wreorder]
modules/bullet/godot_ray_world_algorithm.h:48:7: warning: 'GodotRayWorldAlgorithm::m_ownManifol1d' will be initialized after [-Wreorder]
modules/bullet/godot_ray_world_algorithm.h:46:33: warning: 'const btDiscreteDynamicsWorld* GodotRayWorldAlgorithm::m_world' [-Wreorder]
modules/bullet/godot_ray_world_algorithm.cpp:50:1: warning: when initialized here [-Wreorder]
modules/bullet/godot_result_callbacks.h:91:18: warning: 'GodotAllConvexResultCallback::m_exclude' will be initialized after [-Wreorder]
modules/bullet/godot_result_callbacks.h:89:6: warning: 'int GodotAllConvexResultCallback::m_resultMax' [-Wreorder]
modules/bullet/godot_result_callbacks.h:93:2: warning: when initialized here [-Wreorder]
modules/bullet/godot_result_callbacks.h:142:18: warning: 'GodotAllContactResultCallback::m_exclude' will be initialized after [-Wreorder]
modules/bullet/godot_result_callbacks.h:140:6: warning: 'int GodotAllContactResultCallback::m_resultMax' [-Wreorder]
modules/bullet/godot_result_callbacks.h:147:2: warning: when initialized here [-Wreorder]
modules/bullet/godot_result_callbacks.h:168:18: warning: 'GodotContactPairContactResultCallback::m_exclude' will be initialized after [-Wreorder]
modules/bullet/godot_result_callbacks.h:166:6: warning: 'int GodotContactPairContactResultCallback::m_resultMax' [-Wreorder]
modules/bullet/godot_result_callbacks.h:173:2: warning: when initialized here [-Wreorder]
modules/bullet/godot_result_callbacks.h:195:18: warning: 'GodotRestInfoContactResultCallback::m_exclude' will be initialized after [-Wreorder]
modules/bullet/godot_result_callbacks.h:191:7: warning: 'bool GodotRestInfoContactResultCallback::m_collided' [-Wreorder]
modules/bullet/godot_result_callbacks.h:199:2: warning: when initialized here [-Wreorder]
modules/bullet/rigid_body_bullet.h:200:9: warning: 'RigidBodyBullet::gravity_scale' will be initialized after [-Wreorder]
modules/bullet/rigid_body_bullet.h:199:9: warning: 'real_t RigidBodyBullet::mass' [-Wreorder]
modules/bullet/rigid_body_bullet.cpp:258:1: warning: when initialized here [-Wreorder]
modules/bullet/rigid_body_bullet.h:222:28: warning: 'RigidBodyBullet::force_integration_callback' will be initialized after [-Wreorder]
modules/bullet/rigid_body_bullet.h:219:7: warning: 'bool RigidBodyBullet::isTransformChanged' [-Wreorder]
modules/bullet/rigid_body_bullet.cpp:258:1: warning: when initialized here [-Wreorder]
modules/bullet/rigid_body_bullet.h:220:7: warning: 'RigidBodyBullet::previousActiveState' will be initialized after [-Wreorder]
modules/bullet/rigid_body_bullet.h:208:6: warning: 'int RigidBodyBullet::maxCollisionsDetection' [-Wreorder]
modules/bullet/rigid_body_bullet.cpp:258:1: warning: when initialized here [-Wreorder]
modules/bullet/soft_body_bullet.h:69:9: warning: 'SoftBodyBullet::total_mass' will be initialized after [-Wreorder]
modules/bullet/soft_body_bullet.h:68:6: warning: 'int SoftBodyBullet::simulation_precision' [-Wreorder]
modules/bullet/soft_body_bullet.cpp:38:1: warning: when initialized here [-Wreorder]
modules/bullet/soft_body_bullet.h:76:9: warning: 'SoftBodyBullet::drag_coefficient' will be initialized after [-Wreorder]
modules/bullet/soft_body_bullet.h:61:14: warning: 'btSoftBody* SoftBodyBullet::bt_soft_body' [-Wreorder]
modules/bullet/soft_body_bullet.cpp:38:1: warning: when initialized here [-Wreorder]
modules/bullet/space_bullet.h:97:22: warning: 'SpaceBullet::solver' will be initialized after [-Wreorder]
modules/bullet/space_bullet.h:95:35: warning: 'btDefaultCollisionConfiguration* SpaceBullet::collisionConfiguration' [-Wreorder]
modules/bullet/space_bullet.cpp:333:1: warning: when initialized here [-Wreorder]
modules/bullet/space_bullet.h:101:23: warning: 'SpaceBullet::soft_body_world_info' will be initialized after [-Wreorder]
modules/bullet/space_bullet.h:99:23: warning: 'btGhostPairCallback* SpaceBullet::ghostPairCallback' [-Wreorder]
modules/bullet/space_bullet.cpp:333:1: warning: when initialized here [-Wreorder]
modules/gdnative/nativescript/nativescript.h:79:13: warning: 'NativeScriptDesc::base_native_type' will be initialized after [-Wreorder]
modules/gdnative/nativescript/nativescript.h:73:9: warning: 'String NativeScriptDesc::documentation' [-Wreorder]
modules/gdnative/nativescript/nativescript.h:88:9: warning: when initialized here [-Wreorder]
modules/gdscript/gdscript.h:296:6: warning: 'GDScriptWarning::line' will be initialized after [-Wreorder]
modules/gdscript/gdscript.h:294:4: warning: 'GDScriptWarning::Code GDScriptWarning::code' [-Wreorder]
modules/gdscript/gdscript.h:303:2: warning: when initialized here [-Wreorder]
scene/3d/physics_body.h:544:7: warning: 'PhysicalBone::simulate_physics' will be initialized after [-Wreorder]
scene/3d/physics_body.h:543:7: warning: 'bool PhysicalBone::_internal_static_body' [-Wreorder]
scene/3d/physics_body.cpp:2502:1: warning: when initialized here [-Wreorder]
scene/3d/physics_body.h:546:6: warning: 'PhysicalBone::bone_id' will be initialized after [-Wreorder]
scene/3d/physics_body.h:539:12: warning: 'Skeleton* PhysicalBone::parent_skeleton' [-Wreorder]
scene/3d/physics_body.cpp:2502:1: warning: when initialized here [-Wreorder]
scene/3d/spring_arm.h:44:11: warning: 'SpringArm::mask' will be initialized after [-Wreorder]
scene/3d/spring_arm.h:43:8: warning: 'float SpringArm::current_spring_length' [-Wreorder]
scene/3d/spring_arm.cpp:37:1: warning: when initialized here [-Wreorder]
scene/animation/skeleton_ik.h:159:11: warning: 'SkeletonIK::target_node_override' will be initialized after [-Wreorder]
scene/animation/skeleton_ik.h:152:7: warning: 'bool SkeletonIK::use_magnet' [-Wreorder]
scene/animation/skeleton_ik.cpp:418:1: warning: when initialized here [-Wreorder]
scene/resources/tile_set.h:84:9: warning: 'TileSet::AutotileData::size' will be initialized after [-Wreorder]
scene/resources/tile_set.h:83:7: warning: 'int TileSet::AutotileData::spacing' [-Wreorder]
scene/resources/tile_set.h:92:12: warning: when initialized here [-Wreorder]
scene/resources/tile_set.h:115:12: warning: 'TileSet::TileData::tile_mode' will be initialized after [-Wreorder]
scene/resources/tile_set.h:114:9: warning: 'Color TileSet::TileData::modulate' [-Wreorder]
scene/resources/tile_set.h:120:12: warning: when initialized here [-Wreorder]
servers/physics/body_sw.h:84:19: warning: 'BodySW::direct_state_query_list' will be initialized after [-Wreorder]
servers/physics/body_sw.h:57:11: warning: 'uint16_t BodySW::locked_axis' [-Wreorder]
servers/physics/body_sw.cpp:756:1: warning: when initialized here [-Wreorder]
```
Nothing really relevant for us, but it's not a bad consistency
improvement anyway so worth taking.
Fixes GCC 5 warnings of the form:
core/io/http_client.cpp:288:9: warning: enumeration value 'STATUS_SSL_HANDSHAKE_ERROR' not handled in switch [-Wswitch]
core/io/marshalls.cpp:806:9: warning: enumeration value 'AABB' not handled in switch [-Wswitch]
Those can be trivial cases where adding a default fallback is the solution,
or more complex issues/hidden bugs where missed values are actually meant
to be handled.
Fixes the following GCC 5 warnings:
```
drivers/gles2/rasterizer_canvas_gles2.cpp:814:8: warning: variable 'rt_size' set but not used [-Wunused-but-set-variable]
drivers/gles2/rasterizer_scene_gles2.cpp:2270:11: warning: variable 'vp_height' set but not used [-Wunused-but-set-variable]
drivers/gles2/rasterizer_scene_gles2.cpp:2673:22: warning: variable 'e' set but not used [-Wunused-but-set-variable]
drivers/gles2/rasterizer_scene_gles2.cpp:715:7: warning: variable 'no_cull' set but not used [-Wunused-but-set-variable]
drivers/gles2/shader_gles2.cpp:693:14: warning: variable 'cc' set but not used [-Wunused-but-set-variable]
drivers/gles3/rasterizer_canvas_gles3.cpp:1226:8: warning: variable 'rt_size' set but not used [-Wunused-but-set-variable]
drivers/gles3/rasterizer_scene_gles3.cpp:3039:10: warning: variable 'contrib' set but not used [-Wunused-but-set-variable]
drivers/gles3/rasterizer_scene_gles3.cpp:4504:32: warning: variable 'vp_height' set but not used [-Wunused-but-set-variable]
editor/editor_inspector.cpp:272:9: warning: variable 'guide_color' set but not used [-Wunused-but-set-variable]
editor/editor_themes.cpp:1067:14: warning: variable 'alpha3' set but not used [-Wunused-but-set-variable]
editor/editor_themes.cpp:263:8: warning: variable 'script_bg_color' set but not used [-Wunused-but-set-variable]
editor/plugins/collision_shape_2d_editor_plugin.cpp:326:11: warning: variable 'cpoint' set but not used [-Wunused-but-set-variable]
editor/plugins/mesh_editor_plugin.cpp:72:9: warning: variable 'size' set but not used [-Wunused-but-set-variable]
editor/plugins/shader_editor_plugin.cpp:471:12: warning: variable 'mpos' set but not used [-Wunused-but-set-variable]
editor/plugins/shader_editor_plugin.cpp:89:8: warning: variable 'basetype_color' set but not used [-Wunused-but-set-variable]
editor/plugins/shader_editor_plugin.cpp:90:8: warning: variable 'type_color' set but not used [-Wunused-but-set-variable]
editor/plugins/shader_editor_plugin.cpp:92:8: warning: variable 'string_color' set but not used [-Wunused-but-set-variable]
modules/visual_script/visual_script_editor.cpp:2521:7: warning: variable 'seq_connect' set but not used [-Wunused-but-set-variable]
platform/android/export/export.cpp:580:12: warning: variable 'styles_count' set but not used [-Wunused-but-set-variable]
platform/android/export/export.cpp:584:12: warning: variable 'styles_offset' set but not used [-Wunused-but-set-variable]
platform/osx/export/export.cpp:464:9: warning: variable 'zerr' set but not used [-Wunused-but-set-variable]
scene/2d/tile_map.cpp:260:10: warning: variable 'tcenter' set but not used [-Wunused-but-set-variable]
scene/3d/light.cpp:166:7: warning: variable 'editor_ok' set but not used [-Wunused-but-set-variable]
scene/3d/navigation.cpp:566:11: warning: variable 'closest_navmesh' set but not used [-Wunused-but-set-variable]
scene/gui/rich_text_label.cpp:869:8: warning: variable 'size' set but not used [-Wunused-but-set-variable]
scene/main/viewport.cpp:705:14: warning: variable 'xform' set but not used [-Wunused-but-set-variable]
scene/main/viewport.cpp:706:8: warning: variable 'ss' set but not used [-Wunused-but-set-variable]
scene/main/viewport.cpp:726:14: warning: variable 'xform' set but not used [-Wunused-but-set-variable]
scene/main/viewport.cpp:727:8: warning: variable 'ss' set but not used [-Wunused-but-set-variable]
scene/resources/material.cpp:430:7: warning: variable 'using_world' set but not used [-Wunused-but-set-variable]
servers/visual/shader_language.cpp:2026:7: warning: variable 'all_const' set but not used [-Wunused-but-set-variable]
servers/visual/visual_server_scene.cpp:1383:28: warning: variable 'z_max_cam' set but not used [-Wunused-but-set-variable]
```
Also fixes two [-Wunused-value] warnings:
```
scene/gui/text_edit.cpp:4405:20: warning: statement has no effect [-Wunused-value]
servers/visual/visual_server_scene.cpp:905:48: warning: value computed is not used [-Wunused-value]
```
Some of those are bugs and need further work, they are identified with
`// FIXME` comments.
Also turn off -Wsign-compare warnings in the future, we do not consider them important.
Fixes the following GCC 5 warnings:
```
core/node_path.cpp:279:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
core/oa_hash_map.h:169:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
core/oa_hash_map.h:314:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/gles2/shader_gles2.cpp:985:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/gles3/rasterizer_storage_gles3.cpp:1075:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/pulseaudio/audio_driver_pulseaudio.cpp:343:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
editor/editor_plugin.cpp:525:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
editor/editor_properties_array_dict.cpp:747:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
editor/plugins/spatial_editor_plugin.cpp:2078:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
editor/plugins/spatial_editor_plugin.cpp:4096:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
editor/plugins/sprite_editor_plugin.cpp💯20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/cvtt/image_compress_cvtt.cpp:122:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/cvtt/image_compress_cvtt.cpp:134:77: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/cvtt/image_compress_cvtt.cpp:339:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/etc/image_etc.cpp:222:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/gdnative/register_types.cpp:242:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/gdnative/register_types.cpp:258:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/opensimplex/simplex_noise.cpp:200:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/opensimplex/simplex_noise.cpp:222:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
modules/opensimplex/simplex_noise.cpp:246:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/android/export/export.cpp:1085:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/android/export/export.cpp:1489:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/android/export/export.cpp:1623:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/iphone/export/export.cpp:206:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/iphone/export/export.cpp:356:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/iphone/export/export.cpp:406:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
platform/iphone/export/export.cpp:493:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/3d/audio_stream_player_3d.cpp:420:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/resources/audio_stream_sample.cpp:565:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/resources/audio_stream_sample.cpp:571:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio/audio_rb_resampler.cpp:156:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
```
The following warnings were not fixed, as they implied casting for no gain:
```
core/io/packet_peer.cpp:228:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
core/io/resource_format_binary.cpp:109:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/gles2/rasterizer_scene_gles2.cpp:144:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/unix/file_access_unix.cpp:249:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/3d/voxel_light_baker.cpp:889:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/3d/voxel_light_baker.cpp:1020:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/3d/voxel_light_baker.cpp:1154:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/3d/voxel_light_baker.cpp:2255:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
scene/resources/bit_mask.cpp:336:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio/audio_stream.cpp:141:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio/audio_stream.cpp:150:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio/audio_stream.cpp:154:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio_server.cpp:86:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
servers/audio_server.cpp:89:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
```
Better heuristic for the shortest path algorithm for navigation2D and navigation.
It now will use the shortest distance to the polygon as cost instead of the distance to the center.
This allows more consistency in the manner we include core headers,
where previously there would be a mix of absolute, relative and
include path-dependent includes.
It's shared by both 2D and 3D particles (+ CPU ones), so it makes sense
to have as a common resource. It also allowed to disable compilation of
Particles (3D) when using 'disable_3d'.
Also cleaned up includes in SpatialEditorGizmos and some other places,
as well as dropped dead code in material_editor_plugin.cpp.
Without this change any new PhysicsBody would show deprecation warnings
due to default values for friction and bounce being defined.
It also enforced a physics material override even when using default
values.
