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.
* All pages are now named with lowercased letters with dashes between
letters.
* Added coding style guidelines.
* Extended building documentation with guide how to download Magnum.