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.

sql/tools/test_mobcarddrop.sql

@@ -23,4 +23,7 @@ CREATE TABLE `_mob_card_counter` (
     `count` INTEGER(10)
 );
 
-CALL countMobCardsBySection();
+CALL countMobCardsBySection();
+
+# the query below recovers all MAIN mobs that drops card.
+SELECT cardid, mobid FROM monstercarddata LEFT JOIN drop_data ON monstercarddata.cardid = drop_data.itemid WHERE mobid = dropperid;