GLX_ARB_context_flush_control
http://www.opengl.org/registry/specs/KHR/context_flush_control.txt
GLX_ARB_context_flush_control
	GLX_CONTEXT_RELEASE_BEHAVIOR_NONE_ARB 0x0000
	GLX_CONTEXT_RELEASE_BEHAVIOR_ARB 0x2097
	GLX_CONTEXT_RELEASE_BEHAVIOR_FLUSH_ARB 0x2098
