Bukkit

ADDED:
- Displays whether an Item can be sold/purchased instead of a price of 0$.
- Added the ability to disable item purchasing & item selling. Simply set the price/sell to 0.

FIXES:
- Fixed not being able to detect if an item is sellable or not, thus stealing the items attempted to be sold.
- Fixed sell inventory taking items that arent in the config period.
- Fixed item data values not being set correctly.