LR-99: Battle Engine v1

You're trying to maintain the same information in two places. This is dangerous - what if you forget to update both places? It's easy to do (especially if it's not you updating the code, but another developer making some changes). 

You can look up the weapon's attack using player._weapon.getAttack(). Because of the risks involved in duplicated data, I would not create self._weaponAttack.