Fix being able to butcher corpses with items that don't have cutting quality

Friend of mine noticed that you could butcher corpses with a hammer. After chasing some code, I ended up at this curiously uninmplemented method. Should work now.

It seems like cutting quality needs to be refined a bit. Every tool/weapon that has a cutting quality has a quality of 1, and I feel like butchering a corpse should take more than that. Like, should you really be able to butcher a corpse with an X-acto knife?