DragonEggDrop's data is a lot more encapsulated and secure from external modification (developers, see API changes)
Dragon loot should now spawn properly per-world. There was a chance that the wrong loot would be spawned
Dragon templates are now identified using a unique identifier. This should not change much in game, though this further supports templates added programmatically
Action bar messages will no longer be displayed if the "announce-messages" configuration option is empty (i.e. announce-messages: [])
API: Removed EndWorldWrapper#setRespawnInProgress(boolean). This is now handled internally
API: Removed DEDManager#setDragonBossBarTitle(). This method was unused
API: DEDManager#setCurrentBattle() and DEDManager#getCurrentBattle() have been removed
API: Added EndWorldWrapper#setActiveBattle() and EndWorldWrapper#getActiveBattle(). Replaces the aforementioned removed methods
API: EndWorldWrapper and DragonLoot constructors are now protected. Should not be instantiatable
API: DEDManager#getWorldWrappers() now returns an immutable Collection
API: DragonTemplates now require a String identifier (for those that do not specify a file)
API: Made stricter requirements on null or invalid parameters for most methods and constructors
API: Fixed a typo in DragonTemplate#setSpawnWeight(). Was #setSoawnWeight()