Desktop OpenGL and OpenGL ES 2 support can be switched using CMake
TARGET_GLES option. All functionality not supported in ES is marked in
documentation.
If targetting OpenGL ES, GLES2/gl2.h is included instead of GLEW.
Mesh class now uses VAOs only in desktop OpenGL, in ES the buffers are
bound on each draw call.
CORRADE_GRACEFUL_ASSERT is set only on files where it makes sense, the
rest is shared between main and test libraries. Speeds up the
compilation like infinity times.
CMake 2.8.8 is required for OBJECT library target.
Algorithm used: Pedro V. Sander, Diego Nehab, and Joshua Barczak, Fast
Triangle Reordering for Vertex Locality and Reduced Overdraw, SIGGRAPH
2007, http://gfx.cs.princeton.edu/pubs/Sander_2007_%3ETR/index.php
Also created new shared MeshTools library.