Auto Butcher

Fixed
- Culling did almost no damage, so creatures took a minute or more to
  die instead of being culled cleanly. They're now killed with the
  harvesting tool's own damage type and die on the first pass, leaving a
  corpse the Auto Butcher harvests seconds later.
- The Auto Butcher stopped working after a server restart until it was
  picked up and placed again. It no longer relies on an internal timer
  that didn't survive a world reload.

Changed
- Culling now covers 5% to 50% matured, instead of stopping at 10%. It
  still only targets wild and unclaimed creatures, never your tribe's
  claimed animals.

Logging
- Each cull records how much damage was applied, making it obvious if
  something survives a hit.