Rebalanced Treasure

The amount of gold pieces and how they translated into "XP" was unnecessarily inflated. The following changes have been made:

• All hex keys containing treasure have been updated. Most amounts of treasure have been divided by 10.
• The amount of gp per item has been divided by 10 to match.
• It now requires 100 gp per HD to advance, instead of 1000. 
• Wandering monster treasure amounts have been left unchanged, to make them (potentially) more impactful.