Adds teeth, teeth necklaces, ability to knock teeth out, as well as some butchering stuff
* Moved species and butchering_drops vars from mob/living/simple_animal to mob/living
* Animal species var has been renamed to species_type (to prevent conflict with humans' species var)
* Added a new resurrect() mob proc, which adds the mob to the living mob list, removes it from the dead mob list and removes the butcher proc from the verb list. All instances of "living_mob_list -= M; dead_mob_list |= M" have been replaced with M.resurrect()
* Replaced mob/living/simple_animal/harvest() with mob/living/butcher()
* Added "irregular_plural" variable for stacks
**Aliens and monkeys can be butchered now**
* Butchering non-animals like aliens and monkeys requires you to use the butcher proc, which is added to the mob's verb list on death
* Butchering currently has no effect on the ability to bring the mob back to life
* Their bodies can't be destroyed via butchering, unlike with animals
* Aliens can be declawed (dropping one xenomorph claw) and skinned (dropping some chitin
and an alien skin)
* In addition, teeth may be harvested from aliens, corgis, goliaths, bears, aliens, cluwnes and creatures
**Added claw and teeth necklaces**
* Created by using 5 lengths of cable on a xenomorph claw or on a stack of teeth
* Teeth necklaces track the type and amount of teeth. More teeth may be added to them after creation.
* Teeth necklaces have a prefix depending on the amount of teeth. >=20 = fine, >=35 = well-made, >=50 = masterwork, >=100 = legendary
**Species with claws (tajara) or beaks (vox) can butcher bodies without any tools. When using tools, they do it slightly faster**
* Wearing gloves or masks negates that bonus
**Examining a mob now tells you whether it has been skinned / its teeth were removed / everything else**
**Hitting a human in the mouth with a heavy item or punching him has a chance of knocking some of his teeth out!**
* This has no effect on the gameplay, other than some flavour text on examine
* 1-3 teeth are sent flying! The chance is (force * w_class), capped at 40%. Items with less than 8 force or less than 2 w_class can't knock out teeth.
* For punches, the chance of knocking out teeth is (0.5 * damage), which isn't really a lot.
* Getting punched by a hulk has a minimum of 52.5% chance of knocking out from 9 to 11 teeth! Just like Gregor Clegane
* Spawned teeth inherit their original owner's name (for example: "Dick Johnson's teeth"). Necklaces made from these teeth simply become "human teeth necklace", however
See merge request !114
