Changed some global_list stuff:

>tried to make the comments less confusing.
>Removed the procs for rebuilding the lists (they weren't meant to be used and half were broken anyway).
>added a directory. It maps ckey to client like so directory[ckey] = client. It could be used for PMs, banning, and various other admin tools rather than using \ref[]
>var/list/admins is now a list of clients whom are admins.
>var/list/admin_datums is what var/list/admins used to be. A map from ckey -> admin datum
Most of this is so I can add modular admin ranks in a non-horrendous way and fix some existing issues.
>var/list/client_list is now var/list/clients (laziness sorry)
>removed some needless loops and stuff.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@4951 316c924e-a436-60f5-8080-3fe189b3f50e

code/modules/admin/holder2.dm

@@ -1,8 +1,8 @@
 /client/proc/deadmin()
-	admins.Remove(ckey)
+	admin_datums -= ckey
 	if(holder)	del(holder)
-	src.clear_admin_verbs()
-	admin_list -= src
+	clear_admin_verbs()
+	admins -= src
 	return 1
 
 var/list/admin_datums = list()