full-screen antialiasing support added

[James W. <ja...@fr...>]

I've added support for full-screen antialiasing via the OpenGL 
multisampling feature.  It is implemented for Mac-Carbon and Windows in 
the OpenGL renderer and derived renderers.  However, it's not quite as 
simple as submitting a kQ3AntiAliasModeMaskFullScreen style object. 
When setting up the draw context, you must provide a multisample-capable 
pixel format (by platform-dependent means) as an object property of type 
kQ3DrawContextPropertyGLPixelFormat.

The extra complication is mostly due to Windows.  On Windows, in order 
to get an appropriate function pointer, you must first get a function 
pointer to wglChoosePixelFormatARB, and in order to get that, you must 
already have an OpenGL context set up.  So the typical routine would 
involve creating a dummy window, getting the function pointer, 
destroying the dummy window, and then proceeding to set up the window 
you really want to use.  I didn't want Quesa to get into the business of 
creating and destroying windows.
-- 
   James W. Walker, Innoventive Software LLC
   <http://www.frameforge3d.com/>