Abstract items and show_inv, some other things

Abstract things now cant be neither seen in show_inv nor be interacted
there
Added abstract flag to golem armor so now only he himself can see what
he is wearing(seems reasonable to me)
Added my shitty spriting of proboscis and stings to icons/weapons, not
sure it is right play or do we ever need them at all
Actually changed changeling_powers to work with stingers instead of
proboscis, but dont want to push it yet, maybe people will want one
proboscis for all stings instead of separate stingers for each sting