GL_NV_fragment_coverage_to_color
http://www.opengl.org/registry/specs/NV/fragment_coverage_to_color.txt
GL_NV_fragment_coverage_to_color
	GL_FRAGMENT_COVERAGE_TO_COLOR_NV 0x92DD
	GL_FRAGMENT_COVERAGE_COLOR_NV 0x92DE
	void glFragmentCoverageColorNV (GLuint color)
