TODO

* When updating plant status every turn, any excess growth should be carried over, rather than just stopping
  and resetting growth at the next stage to 0 (2017-03-27, kmw)
* Make savefiles portable--this will require paying attention to endianness, at the very least (2017-04-11,
  kmw)
* Add creature food preferences, and update creature AI to respect them when eating (2017-05-28, kmw)
* Creatures should prefer not to waste food by eating items that give more nutrition value than what they
  need, unless desperately hungry (2017-06-26, kmw)
* Creatures should avoid eating corpses of former allies (2017-06-26, kmw)
* Creatures should pick up unneeded food and carry it around for later (2017-06-26, kmw)
* It should be possible to start eating, get some nutrition, then stop and save the rest for later
  (2017-06-26, kmw)
* Hungry creatures should actively seek out food, rather than simply hoping they randomly pass by
  some (2017-06-26, kmw)
* Creature weapon-wielding AI should handle the case where attempting to wield a two-handed weapon fails
  because of wearing a shield (2017-09-08, kmw)
* Creatures should be able to attack with throwing weapons, and carry several of them around (2017-09-14,
  kmw)
* Consider giving an error or message of some sort if the player tries to equip armor in a slot that's
  already in use, rather than just silently replacing it (2017-12-23, kmw)