Gold Pool implemented for Vendors

It appears that my solution breaks persuasion gold for some reason. I
may be wrong. I can’t see where this could be happening as the files
I’ve changes should not affect persuasion at all.
getBaseGold implemented in MWWorld::Class for NPC and Creature

Implemented a getBaseGold() to get the vendor gold base
NPC gold base now can come from mNpdt12 and mNpdt52
Merge remote-tracking branch 'jeffreyhaines/master'