GLX_EXT_import_context
https://www.khronos.org/registry/egl/specs/eglspec.1.5.pdf
GLX_EXT_import_context

	GLX_SHARE_CONTEXT_EXT 0x800A
	GLX_VISUAL_ID_EXT 0x800B
	GLX_SCREEN_EXT 0x800C
	void glXFreeContextEXT (Display* dpy, GLXContext context)
	GLXContextID glXGetContextIDEXT (const GLXContext context)
	Display* glXGetCurrentDisplayEXT (void)
	GLXContext glXImportContextEXT (Display* dpy, GLXContextID contextID)
	int glXQueryContextInfoEXT (Display* dpy, GLXContext context, int attribute, int* value)
	typedef XID GLXContextID