* Fix a bug which got unnoticed for a very long time in the cave driver related to synchronization between sprites and bg layers (apparently it was here since 0.50.6).
* cps1 : reset the video priorities when loading a new game. Before that if you loaded 1941 after varth, you got some very weird video priorities in 1941 (sprites partially hidden).
* Loading a savegame from the gui now automatically returns to game (for neoraine too).