KeeperRL Alpha 29 hotfix 3 released

This patch fixes most of the remaining crashes in Alpha 29 and improves end-game performance by a large margin.

• Creatures that have archery training potential can wield ranged weapons, even if they're ranged damage attribute is 0.
  
• Stopped AI from casting offensive spells on captured enemies.
  
• Fixed issue with tooltip covering item pop-up menu in the workshops menu.
  
• 'Stones' terrain feature can be removed with the "remove construction" order.
  
• Fixed construction debt inconsistency which caused crashes.
  
• Fixed crash caused by an item cloned by the double trouble spell disappearing while being equipped.
  
• Fixed a rare (and old!) task handling crash caused by a poor RNG generating task ids that weren't unique.
  
• Fixed a crash when there are no more healthy body parts left to severe.
  
• 'Other' items in minion's possession are stacked to stop the UI from potentially trying to render thousands of items.
  
• Fixed bookcase ascii symbol.
  
• Optimized spell casting AI.
  
• Optimized imp/worker task processing, including the scenario when a huge number of 'dig' orders are placed.
  
• Optimized general creature handling.