Sanity checks, miscellaneous bugfixes, failsafes.

Disposals no longer indiscriminately let items land inside it - the items have to have been thrown by someone.

The ongoing attempt to fix the thousands of runtimes plaguing the game.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@3195 316c924e-a436-60f5-8080-3fe189b3f50e

code/modules/mob/mob.dm

@@ -632,7 +632,7 @@
 				return.
 
 			var/t = input("Message:", text("Private message to [C.key]"))  as text|null
-			if (!t || !usr || !C)
+			if (!t || !usr || !C || !usr.client)
 				return
 			if (usr.client && usr.client.holder) //Admin is messaging a player
 				C << "\red <font size='4'><b>-- Administrator private message --</b></font>"