Auto Butcher

Fixed
- The Auto Butcher stopped working after a server restart or any world
  reload. Its timer only started when the structure was first placed, so
  a harvester that had been saved and loaded sat idle until it was picked
  up and placed again. It now restarts itself when the world loads and
  when it comes out of stasis.

Added: baby culling (off by default)
- New radial option, "Enable culling".
- While on, the Auto Butcher kills wild and unclaimed babies under 10%
  matured inside its range, then harvests them like any other corpse.
- Your own tribe's claimed creatures are never touched, and neither is
  anything belonging to another tribe.
- Culling only runs when a harvesting tool is loaded, so it won't leave
  corpses it can't process.
- The setting is saved with the structure and survives restarts.

Logging
- Each cull candidate is logged with its age, team, owner and tribe,
  which makes it possible to see what the structure is considering
  without turning culling on.