closets can no longer contain a near infinite amount of mobs.

Closets and its children can no longer contain a near infinite amount of mobs. Fixes #5142 .

* Adding a mob_size var to mob/living to distinguish small, human-sized and large mobs .
 All closets can still contain the same amount of small sized mobs as before(mouse, parrot,pAI, viscerator, lizard, chick).
They can no longer contain large mobs (alien emperess, blobbernaut, juggernaut, hostile tree, goliath).
They can contain a few human sized mobs (three for bodybags, two for closets and other children (numbers can be changed)).

* fixing a very old typo in bodybag.dm