Moogle Shop needs finishing

[Wehavecookies56]

This will allow the player to spend munny and also sell items for munny.

What this entails:

• [x] A registry for items/blocks that are worth munny
• [x] An interface that allows you to choose buy or sell
• [x] Buying an item will take the munny that it's worth and give the player the item.
• [x] Selling an item will give the munny that it's worth divided by 2 and take the item from the player
• [x] Register all the items that can be sold, and add all the items which should be bought.