Have begun work on this. The constants are added, though they do not appear in my version of FreeGLUT. I've added the freeglut and freeglut32 dll names, but at the moment I don't have them selectable. The HAVE_FREEGLUT flag should be properly set now, and the wrapper operations should only occur if __glutCreateWindowWithExit exists (so should not occur for freeglut). Will need to test the changes on Win32, of course.