Removed sleep/rest verb from non-carbon mobs, slimes and brains.
Fixed the possibility to forcefeed brains snacks.
Removed the countdown of various status effects in brain's life() proc that shouldn't happen to brains anyway.
Moved mob_sleep and lay_down away from screen.dm as there hasn't been an ui item associated with them forever.
mob_sleep and lay_down are now procs of mob/living, added as verbs to whichever mob should have the ability to sleep or lay down (alien, monkey, human as of now)
Merge pull request #1217 from dumpdavidson/nosleepAI

Removal of sleep/rest verbs for most mobtypes, fix for forcefeeding brains