Cleanup idle callbacks when unframing windows. Prevent calling frame draw
callback on already destroyed windows (SEGV).

--- xfwm4-4.6.1.orig/src/client.c.orig	2011-12-18 23:32:41.260000247 +0100
+++ xfwm4-4.6.1.orig/src/client.c	2011-12-18 23:33:54.459999471 +0100
@@ -2122,6 +2122,9 @@ clientUnframe (Client * c, gboolean rema
     screen_info = c->screen_info;
     display_info = screen_info->display_info;
 
+    while (g_idle_remove_by_data(c)) {
+        TRACE ("WARNING: some entries left in idle queue; removed");
+    }
     clientRemoveFromList (c);
     compositorSetClient (display_info, c->frame, NULL);