When setting the event structure fields, don't die when the widget

name is not registered; simply use the string.  This happens for
tear-off widgets (e.g. if you've registered enter/leave events for the
menu).

Lib/lib-tk/Tkinter.py

@@ -585,7 +585,10 @@ class Misc:
 		e.keysym = K
 		e.keysym_num = tk.getint(N)
 		e.type = T
-		e.widget = self._nametowidget(W)
+		try:
+			e.widget = self._nametowidget(W)
+		except KeyError:
+			e.widget = W
 		e.x_root = tk.getint(X)
 		e.y_root = tk.getint(Y)
 		return (e,)