cleaned up power sink, talisman bug

Split from #480

* Powersink code was kinda nasty with it overall being an FSM, but the transitions were a pile of redundant variable changes, and it was hard to tell exactly what changed and what didn't when various events happened. I mainly did this because it seemed to easy for it to become bugged so that it would keep draining while unattached or something.
 * As another, this fix also properly disconnects the powersink if the wire underneith it is cut. I don't think that bug has been reported yet. 
* Also fixed cultist talismans not drop_item()'ing when used up #203