GL_EXT_framebuffer_sRGB
http://developer.download.nvidia.com/opengl/specs/GL_EXT_framebuffer_sRGB.txt
GL_EXT_framebuffer_sRGB
	GL_FRAMEBUFFER_SRGB_EXT 0x8DB9
	GL_FRAMEBUFFER_SRGB_CAPABLE_EXT 0x8DBA