GL_MESAX_texture_stack
http://www.opengl.org/registry/specs/gl/MESAX/texture_stack.txt
GL_MESAX_texture_stack
	GL_TEXTURE_1D_STACK_MESAX 0x8759
	GL_TEXTURE_2D_STACK_MESAX 0x875A
	GL_PROXY_TEXTURE_1D_STACK_MESAX 0x875B
	GL_PROXY_TEXTURE_2D_STACK_MESAX 0x875C
	GL_TEXTURE_1D_STACK_BINDING_MESAX 0x875D
	GL_TEXTURE_2D_STACK_BINDING_MESAX 0x875E