Removed villager bomb trades

- 'Barnes' trades never actually worked; removed
- Removed bomb and bomb bag trades from villagers
- Gorons still able to sell bombs
Updated EntityNpcBase

Copied villager behavior for setRevengeTarget: attacking NPCs affects
player reputation
All NPCs now respond to masks with dialogue
Added Barnes

- Villagers no longer sell bombs or bomb bags
- All NPCs respond to being clicked with a bomb
- Placeholder texture for Barnes
Fix name tag not carrying over
Fix gunpowder not being given
Added Mask Salesman model
Fixes issue # 22

Bags without NBT or without the correct key would return a capacity of
0, thus allowing them to be combined with another bag without increasing
the actual capacity.