Vivid Birds

While this release does not add anything new to the game (and actually removes some things!), a lot of changes have been made to fix some issues and properly register entities as mod-specific. This is incompatible with previous versions and will break stuff when added to existing worlds!

• a whole bunch of changes have been made to ostriches, to clean up their code and remove overly complex behaviour (some of this might return, depending on requests):
  • removed the old throwable ostrich eggs (which were basically a copy of chicken eggs and a temporary solution)
  • completely removed nest generation for now (was causing world corruption)
  • can be bred with wheat instead
  • can only be healed with wheat for now
  • removed "experience" system for damage, set to constant value of 5
• removed a bunch of randomness from stats like damage and health, and growing time of tameable birds
• changed egg colours from really bad to... less bad?
• increased spawn rates previously, it was nearly impossible to find birds in the wild) - please tell me whether they are reasonable now
• lots of minor changes and refactoring