Accept focus-change-event if NOTIFY-MODE is WHILE-GRABBED.

This allows focus changes to happen while a key is pressed and seems
to remedy the problem of having multiple windows, painted as
"focused".

src/manager.scm

@@ -460,7 +460,9 @@
       (if (window-exists? dpy (client:window client))
 	  (let ((mode (focus-change-event-mode xevent))
 		(detail (focus-change-event-detail xevent)))
-	    (if (and (eq? mode (notify-mode normal))
+
+	    (if (and (or (eq? mode (notify-mode normal))
+                         (eq? mode (notify-mode while-grabbed)))
 		     (memq detail (list (notify-detail nonlinear)
 					(notify-detail nonlinear-virtual)
 					(notify-detail virtual)