Removed NullAI, AIFactory and AIWrapper. Renamed Keeper2AI to KeeperAI
Most of the AIWrapper has been moved to BaseAI (to be shared between AIs)
The factory has been moved to the AIManager
fixes #328
Fixed bugs within dormitory:
- Beds were misplaced
- When some tiles were destroyed, some beds (bigger that 1x1) were not removed
- When some tiles were destroyed, some beds were removed when they should not due to wrong activespot management (also true for treasury)
- Merged some functions that were splitted during first attempts to fix multiplayer (deprecated by later commits)

fixes #243
fixes #326
Forced to stop handling messages when the mode changes while launching a replay to allow the new mode to take place before related messages are processed (fixes the wrong mode assertion while launching a replay)
+ Added game time display when pressing F11