Implement Refunds at purchase price and current price

[wgaylord]

This fixes the refund system for deleting items and extends it,

It allows for refunding items at the purchase price (price at time the player purchased it) OR At current price of the item

When refunding at current price it uses the currency based on what currency was used to purchase it.

This requires the fix to LibK to be merged to actually work.

[wgaylord]

Any further comments?

[ValentinFunk]

Any further comments?

Hey sorry for the delay here and thanks for the ping! Added some comments above