Don't traceback when wakeup() is called when the window has been destroyed.

This can happen when a torn-of Windows menu references closed windows.
And Tim Peters claims that the Windows menu is his favorite to tear off...

Tools/idle/WindowList.py

@@ -48,6 +48,11 @@ def get_title(self):
         return self.wm_title()
 
     def wakeup(self):
+        try:
             self.tkraise()
             self.wm_deiconify()
             self.focus_set()
+        except TclError:
+            # This can happen when the window menu was torn off.
+            # Simply ignore it.
+            pass