+ Added IBossDeathHandler to add custom handlers for AutoSpawn
+ Modified AutoSpawnSettings to have a new method shuffleEntitiesList for when a boss is attempted to spawn
+ Modified IntervalSpawnElement to have a new method spawnAfterLastBossIsKilled
+ Added implementation of IBossDeathHandler into BossDeathListener
+ Continued implementation of the AutoSpawn system
+ Updated the autospawns.json file to be suitable for abstract spawn type
+ Added AutoSpawnFileManager and Handler
+ Created AutoSpawnManager