Fixes reported logically dead codes by Coverity
* image.cpp: Doesn't really need any modification. But to remove the bug
report then we have to move the MAX call away from the for loop
statement.
* rasterizer_gles3.cpp: Removes unnecessary elif condition since it is
checked earlier in the function
* collada.cpp: If stamement never reached due to macro ERR_CONTINUE does
the same.
* navigation_mesh.cpp: Variables should always be null - however, also
checked for the very same condition in their function call. Leaving this
for review (whether the function call is necessary or not)
* path_editor_plugin.cpp: If cancel is true, then it should restore the
edited value to the original provided.
http://docs.godotengine.org/en/3.0/classes/class_editorspatialgizmo.html#class-editorspatialgizmo-commit-handle
* spatial_editor_gizmos.cpp: the very condition of i >= 3 is
predetermined in the if case right before it. Thus case 1 is always '1'
and case 2 is always '-1'
* grid_map_editor.cpp: Same as above in spatial_editor_gizmos.cpp
* voxel_light_baker.cpp: Same as above in spatial_editor_gizmos.cpp
* visual_server.cpp: Same as above in spatial_editor_gizmos.cpp
* visual_script_expression.cpp: char '-' is already true in the switch
case mechanism. Thus it can never reach to default case.
* particles.cpp: Case 'PARAM_MAX' is unreachable due to index checking
right before the switch execution.
* shader_language.cpp: Invalid index is handled in switch default case.
`type < TYPE_FLOAT && type > TYPE_VEC4` -> `(type < TYPE_FLOAT || type > TYPE_VEC4`)
Fixes the "always false problem" in TODO comment.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
