More End Dungeons [Achievements Enabled]

Updated 1.0.1:

• The spawn rate of all structures has been greatly reduced.
  
• Structures can no longer spawn on the main End island.
  
• The loot from chests in all structures has been balanced according to their difficulty; larger structures will provide better loot, while smaller ones will provide worse loot.
  
• 8 new structures have been added:
  
• 1 End Castle
  
• 1 End Small Castle
  
• 4 Purpur Castles
  
• 2 End Towers