Added scriptable move triggers for AIPlayers. Fixes an issue where AIPla...

These changes fix the issues described in [this forum thread](http://www.garagegames.com/community/forums/viewthread/140646).

Fixing the above issue has resulted in the ability to set any supported move trigger on an aiplayer from script. For example, to make bob crouch:
bob.setMoveTrigger($player::crouchtrigger);