Bukkit

• Allow altering the profession of villagers
• Update xp regeneration system, make it a separate "mana" system.
• Fix some strange behavior with how material positions are saved when there are too many for the wand to hold.
• When randomizing a wand, make sure it has at least enough max xp to cast its most expensive spell.
• Fix some of the xp-related issues, particularly enchanting and the mana system
• Bugfixes to the arrow spell, introduces in 2.5.4
• Tested with the 1.7.2 Bukkit dev release

Issues I've noticed in 1.7.2 so far:
- The lightning spell creates no visual effect
- Enchanting is a little wonky, something to do with swapping out the item for an enchantable one, I think. Seems to work though.