KeeperRL 1.1.5 is out

This fixes another two other issues found in 1.1.3. If you find that any other enemies are too hard or too easy to kill with recent changes, please let me know.

• Made it possible again to cut off hydra's heads.
  
• Only up to 20 body parts will count towards Necromancer's abominations health to avoid them being near invincible.