Minor tweaks

- readjusted Goron Tunic damage (again) to 4 instead of 2
- increased cost of Fire Bomb trade from 5 to 10 emeralds
- added config option for fairy spawner rates
- added config option for fairy spawner reset time
- fixed bug with hookshoot range config option
- adjusted some default config values
- slightly increased max fairy capacity of spawners
- added check for nearby fairies; only spawns up to 4 at a time
- spawner now uses calendar date for next respawn
- dungeon core has and saves 'isLocked' field for future use