add WM_TRANSIENT_FOR event support: moves dialogs, toolbars and such to

the group of the main application window; based on a diff from Alexander
Polakov with CLIENT_IGNORE flag suggestion from oga@.

ok oga@

xevents.c

@@ -191,6 +191,9 @@ xev_handle_propertynotify(XEvent *ee)
 		case XA_WM_NAME:
 			client_setname(cc);
 			break;
+		case XA_WM_TRANSIENT_FOR:
+			client_transient(cc);
+			break;
 		default:
 			/* do nothing */
 			break;