Robot hud element

Created by: clusterfack

Patches up another obj/screen leak, this time with robot hud storage. Obj/screen pooling breaks when pooling objects aren't refreshed by a new hud in mob/login(), due to the fact all objects currently on the client.screen are pooled so they can be refreshed at login()

Robot module huds were not replaced properly by this thanks to someone cough ririchiyo cough putting them in new() instead of where all other hud elements are kept.