Multi World NPCs + patch on Player interactions

Made NPCs now work properly on multiworld system. Solved multiple issues
regarding Player Shops not giving back items properly when owner exits.
Added restriction on changing channels at FM rooms, preventing shop
owner entering Cash Shop.

scripts/npc/2012021.js

@@ -0,0 +1,30 @@
+function start() {
+    if(cm.haveItem(4031331)){
+        var em = cm.getEventManager("Cabin");
+        if (em.getProperty("entry") == "true") {
+            cm.sendYesNo("Do you wish to board the flight?");
+        } else {
+            cm.sendOk("The flight has not arrived yet. Come back soon.");
+            cm.dispose();
+        }
+    } else {
+        cm.sendOk("Make sure you got a Leafre ticket to travel in this flight. Check your inventory.");
+        cm.dispose();
+    }
+}
+function action(mode, type, selection) {
+    if (mode <= 0) {
+	cm.sendOk("Okay, talk to me if you change your mind!");
+        cm.dispose();
+	return;
+    }
+
+    var em = cm.getEventManager("Cabin");
+    if (em.getProperty("entry") == "true") {
+        cm.warp(200000132);
+        cm.gainItem(4031331, -1);
+    } else {
+        cm.sendOk("The flight has not arrived yet. Come back soon.");
+    }
+    cm.dispose();
+}