It seems to handle mode switching slightly better in OpenGL: I still
get the "windows resize to the fullscreen resolution" and "maximized
windows go under the taskbar" problems occasionally when I change the
resolution in game, but they no longer happen when I simply play the game
in fullscreen. We also can avoid reloading textures on mode change in
many cases. (This is not going into the 3.9 release.)
Glenn Maynard
c88ddccc73