Fixed windows crash on exit (SDL_QuitSubSystem).
Fixed windows crash on exit (SDL_QuitSubSystem).

svn path=/trunk/libavg/; revision=3808

scotty007/libavg,th3infinity/libavg,scotty007/libavg,th3infinity/libavg,yyd01245/libavg,hoodie/libavg,hoodie/libavg,th3infinity/libavg,libavg/libavg,yyd01245/libavg,yyd01245/libavg,scotty007/libavg,hoodie/libavg,libavg/libavg,libavg/libavg,yyd01245/libavg,scotty007/libavg,hoodie/libavg,libavg/libavg,th3infinity/libavg