Track body wetness

Here is my attempt at storing body wetness in its own entity and not in the morale. Unfortunately, I have done something silly and I get a crash. I am hoping it's something obvious, but breakpoints don't work for me in C::B.
For future reference, savegame_legacy probably shouldn't need updating unless you need to initialize something specially, those body wetness values will never be present since we never write them to legacy saves.