Quick patch for the last commit

Fixed some bugs that appeared with the last commit. Added more info on
the event functions documentation.

scripts/event/LudiPQ.js

@@ -146,6 +146,8 @@ function scheduledTimeout(eim) {
         }
 }
 
+function playerUnregistered(eim, player) {}
+
 function playerExit(eim, player) {
         eim.unregisterPlayer(player);
         player.changeMap(exitMap, 0);
@@ -233,4 +235,3 @@ function allMonstersDead(eim) {}
 function cancelSchedule() {}
 
 function dispose(eim) {}
-