Templated several of the utility functions and added for_each_n.
Initialize the lights with for_each_n.
Added vertex array objects.
Split fixie.cpp into fixie_es fixie_es_ext and fixie_ext.
Expose texture::generate_mipmaps publically.
Added stubs for supporting framebuffer object extensions.
Added stubs for supporting vertex array object extensions.
Implemented GL_OES_vertex_array_object.