Trading and other fixes

- Config: Number of boss mobs to spawn for Boss Dungeon battles
- Config: updated "Boss health multiplier" description; be sure to use
the new one if you changed this value
- Removed swing delay for one-handed swords, including all versions of
Master Sword
- Villagers during Biggoron's Trading Sequence no longer limited to
trading only once
- Villagers getting multiple, identical trade entries for various custom
trades
- Odd Egg achievement was apparently removed during a previous update,
but is once again attainable