Runtime fixes

Moved delete to trial admins because they can already mass delete and that's not particularly as helpful as regular delete (but a lot more destructive)
Trialmins can now toggle adminhelp sounds without observing

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@3397 316c924e-a436-60f5-8080-3fe189b3f50e

code/modules/mob/new_player/preferences.dm

@@ -374,6 +374,8 @@ datum/preferences
 
 
 	proc/process_link(mob/user, list/link_tags)
+		if(!usr)
+			return
 		if(link_tags["occ"])
 			if(link_tags["cancel"])
 				user << browse(null, "window=\ref[user]occupation")