GL_EXT_discard_framebuffer
http://www.opengl.org/registry/specs/EXT/discard_framebuffer.txt
GL_EXT_discard_framebuffer

	GL_COLOR_EXT 0x1800
	GL_DEPTH_EXT 0x1801
	GL_STENCIL_EXT 0x1802
	void glDiscardFramebufferEXT (GLenum target, GLsizei numAttachments, const GLenum* attachments)