GL_NV_conditional_render
http://www.opengl.org/registry/specs/NV/conditional_render.txt
	GL_QUERY_WAIT_NV 0x8E13
	GL_QUERY_NO_WAIT_NV 0x8E14
	GL_QUERY_BY_REGION_WAIT_NV 0x8E15
	GL_QUERY_BY_REGION_NO_WAIT_NV 0x8E16
	void glBeginConditionalRenderNV (GLuint id, GLenum mode)
	void glEndConditionalRenderNV (void)
