demos: add some fflushes for windows

progs/demos/arbfplight.c

@@ -92,6 +92,7 @@ static void Redisplay( void )
 	 GLfloat seconds = (t - T0) / 1000.0;
 	 GLfloat fps = Frames / seconds;
 	 printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
+         fflush(stdout);
 	 T0 = t;
 	 Frames = 0;
       }