Core/SmartScripts

* `SMART_ACTION_CALL_KILLEDMONSTER` rewritten to properly give kill credit when target type is set.
* Allow `SMART_ACTION_TELEPORT` to teleport creatures also.

Other:
* Load grid before teleporting a creature to it.
* Relocate passengers when teleporting a vehicle to prevent vehicle despawn.

Adding core changes as I'm trying to script ``As Hyjal Burns`` quest without C++.