GLX_OML_swap_method
http://oss.sgi.com/projects/ogl-sample/registry/OML/glx_swap_method.txt
	GLX_SWAP_METHOD_OML 0x8060
	GLX_SWAP_EXCHANGE_OML 0x8061
	GLX_SWAP_COPY_OML 0x8062
	GLX_SWAP_UNDEFINED_OML 0x8063