Bugfix: Looting should end when evac'd/ported

Mentioned here:-
http://www.peqtgc.com/phpBB3/viewtopic.php?f=17&t=15041

(not sure about the X button thing, I think he may have just taken the TL)

When you are ported, TL'd, evac'd,  ZonePC is called but it doesn't check if you were looting, so if you're TL'd then you can lock the corpse forever.

To ensure the corpse is unlocked, the client has to store the entity id of the mob it is looting, so that when looting is ended in this manner and not from packets sent from the client to end looting, the corpse can be released. The alternative was to iterate through all entities to see whose "BeingLootedBy" matched the clients ID but I think that would be slower.

So SetLooting now needs the corpse ID, or 0 (to indicate nothing is being looted).