GLUTSurfaceTexture

A fairly simple example of using glutSurfaceTexture to texture from one surface to 
another.  This sample requires glut 3.1+ (available in Mac OS X v10.2.3 or later).  

Surface textre API notes:
	glutSurfaceTexture  (GLenum target, GLenum internalformat, int surfacewin)
	
	target: Specifies an allowable 2D OpenGL texture target such as GL_TEXTURE_2D 
		or GL_TEXTURE_RECTANGLE_EXT.
		
	internalformat: Specifies the internal texture layout, which must be a supported 
		format listed on table 3.15, 3.16, 3.17 or 3.18 of the OpenGL 1.3 Specification.
		
	surfacewin: Specifies the GLUT window from which to get the texture.

	glutSurfaceTexture allows direct texturing from a window by using the window contents
	as the source data for the texture, behaving much the same way as glTexImage2D. The
	texture target, internal format must be supported the renderer of the target context.
	Additionally, the source window geometry must be compatible with the texture target.
	Thus, if the texture target is GL_TEXTURE_2D, the window must conform to power of two
	dimensions.
	
	This routine is designed for performance so the graphics driver will attempt to provide an
	optimum data path, keeping the data in VRAM if possible. Also, there is no window tracking,
	thus both target and source windows must be on the same virtual screen (renderer) or failure
	(likely lack of texturing) will result.

