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/game/objects/radio/radio.dm

@@ -261,6 +261,8 @@ var/GLOBAL_RADIO_TYPE = 1 // radio type to use
 			channel = null
 		if (!istype(connection))
 			return
+		if (!connection)
+			return