+ Fully implemented Boss listeners for damage handling
+ Switched around the bosses.json layout a bit to handle multiple mobs per boss easier
+ Updated mechanics to handle all bosses in a activebossholder
Added BossesFileHandler, BossesFileManager as well as updating MainStatsElement in the bosses.json file to allow for multiple bosses (stacking) as well as updating the EntityTypeMechanic to support the new multiple bosses option. Also finished off the createBaseBossEntity method in the BossAPI.