GL_NV_sRGB_formats
http://www.opengl.org/registry/specs/NV/sRGB_formats.txt
GL_NV_sRGB_formats

	GL_ETC1_SRGB8_NV 0x88EE
	GL_SRGB8_NV 0x8C41
	GL_SLUMINANCE_ALPHA_NV 0x8C44
	GL_SLUMINANCE8_ALPHA8_NV 0x8C45
	GL_SLUMINANCE_NV 0x8C46
	GL_SLUMINANCE8_NV 0x8C47
	GL_COMPRESSED_SRGB_S3TC_DXT1_NV 0x8C4C
	GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_NV 0x8C4D
	GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_NV 0x8C4E
	GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_NV 0x8C4F
