Fix a variety of ref counting issues

This patch resolves a number of ref leaks that occur primarily on Asterisk
shutdown.  It adds a variety of shutdown routines to core portions of
Asterisk such that they can reclaim resources allocate duringd initialization.

Review: https://reviewboard.asterisk.org/r/2137



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@374177 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/cel.c

@@ -711,6 +711,10 @@ static void ast_cel_engine_term(void)
 		ao2_ref(appset, -1);
 		appset = NULL;
 	}
+	if (linkedids) {
+		ao2_ref(linkedids, -1);
+		linkedids = NULL;
+	}
 }
 
 int ast_cel_engine_init(void)