Change back automatic draw method to triple buffer for Intel cards, overlap is

not working reliable and flickering on various configurations, will try to find
out what these are, but for now probably better to have correct than fast drawing.

source/blender/windowmanager/intern/wm_draw.c

@@ -686,9 +686,11 @@ static int wm_automatic_draw_method(wmWindow *win)
 		/* ATI opensource driver is known to be very slow at this */
 		if(GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_UNIX, GPU_DRIVER_OPENSOURCE))
 			return USER_DRAW_OVERLAP;
+#if 0
 		/* also Intel drivers don't work well with this */
 		else if(GPU_type_matches(GPU_DEVICE_INTEL, GPU_OS_ANY, GPU_DRIVER_ANY))
 			return USER_DRAW_OVERLAP;
+#endif
 		/* Windows software driver darkens color on each redraw */
 		else if(GPU_type_matches(GPU_DEVICE_SOFTWARE, GPU_OS_WIN, GPU_DRIVER_SOFTWARE))
 			return USER_DRAW_OVERLAP_FLIP;