Exp gain & Chaos scroll fix + Diet's MK Overhaul

Fixed issues with negative experience being distributed to characters
when killing a mob, rendering "Exp reset". Fixed chaos scroll behaving
oddly. Refactored debuff expirations to manage one list with registered
debuffs and expire times, thus lifting some load from the TimerManager.
Added concurrency protection on how World deals with parties. Thanks to
the DietStory dev team, fixed some issues with the MK maps.

scripts/portal/end_cow.js

@@ -0,0 +1,22 @@
+/*
+	By: Kevin
+	Map: Hidden Chamber - The Nautilus - Stable (912000100)
+	Quest: Find Fresh Milk (2180)
+*/
+
+function enter(pi){
+	if (pi.isQuestStarted(2180) && (pi.hasItem(4031847) || pi.hasItem(4031848) || pi.hasItem(4031849) || pi.hasItem(4031850))){
+		if (pi.hasItem(4031850)){
+			pi.warp(120000103);
+			return true;
+		}
+		else{
+			pi.getPlayer().dropMessage(5, "Your milk jug is not full...");
+			return false;
+		}
+	}
+	else{
+		pi.warp(120000103);
+		return true;
+	}
+}