Readded kitty ears

Not on the map yet, gonna do that next I suppose.
Merge branch 'master' of https://github.com/tgstation/-tg-station into revenge_of_kitty_ears

Conflicts:
	icons/mob/head.dmi
	icons/obj/clothing/hats.dmi

Fucking laser tag helmets were conflicting. Lucky me!
Merge pull request #2850 from MrPerson/revenge_of_kitty_ears

Return of kitty ears