Walking Mushrooms will now hunt and eat eachother

Walking shrooms will hunt and eat their fellow shrooms (and only their fellow shrooms)

When they eat another one, they dispose of the corpse, they get a little stronger, heal to full, spawn more mushroom slices when butchered, and have better quality slices when butchered!

Don't smack em around yourself though, or you'll bruise them and mushrooms won't gain levels from eating a bruised 'shroom!

(Moved walking shrooms into simple_animal/hostile from just simple_animal