GL_EXT_cull_vertex
http://www.opengl.org/registry/specs/EXT/cull_vertex.txt
GL_EXT_cull_vertex
	GL_CULL_VERTEX_EXT 0x81AA
	GL_CULL_VERTEX_EYE_POSITION_EXT 0x81AB
	GL_CULL_VERTEX_OBJECT_POSITION_EXT 0x81AC
	void glCullParameterdvEXT (GLenum pname, GLdouble* params)
	void glCullParameterfvEXT (GLenum pname, GLfloat* params)
