The reordering of the SConscript includes allows to ensure that
stuff like the builtin zlib headers will be available for libpng.
Also moved glew back into global env, otherwise windows seems
not to find it... Kind of shooting in the dark with this multi-env
setup.
Not fully happy about the way this one interacts with the various
platforms. Maybe the platform_config.h should be generated by the
SCsub instead of passing a define just to know where is the header.
This removes a custom redefinition of glewGetProcAddress,
which was apparently necessary for older Macs with buggy OpenGL
(see #5087).
The added source files are as provided in the upstream tarball.
This allows us not to have to hack our definitions in the upstream files,
making it easier to upgrade to newer versions in the future.
For the include paths to work, the headers are moved to a GL subfolder to
match their upstream location.
-=-=-=-=-=-=-=-=-=-
-Moved drawing code to a single function that takes linked list (should make it easier to optimize in the future).
-Implemented Z ordering of 2D nodes. Node2D and those that inherit have a visibility/Z property that affects drawing order (besides the tree order)
-Removed OpenGL ES 1.x support. Good riddance!
