Mythic Mounts

- Added a Summoning Staff item that can warp mounts to a player/the ground
- Added the ability to give wander/follow/sit commands to mounts in-game using either the command item or a summoning staff
- Improved the follow-owner AI for flying, swimming, and lava-walking mounts
- Added the ability to enable 3rd person perspective for flying mounts in the config file (clientside)
- Reduced head jitter when riding flying mounts without gravity and fixed a bug with client-side gravity options overriding server settings
- Added the ability to create biome, item, and spawn groups in the config file to help manage settings
- Improved the way caves are detected in the spawning algorithm - no more surprise house geckotoas!
- Added support for SpawnFreq and SpawnOffset to the spawning algorithm
- Added support for general biome categories to the spawning algorithm
- Added global debug and global mob cap settings to the config and fixed a bug with mob cap limits
- Changed enableCreativeFlight to enableFlyingGravity in the config
- Generally reduced volume of mount sounds
- Changed mount diet settings to use actual items instead of herbivore/carnivore/omnivore values
- Changed the resource identifiers for the geckotoa and netherbat spawn eggs
- Converted the config to json format, re-wrote the parser, and fixed some typos in the config
- Geckotoas should be rare again