Encode Unicode arguments to split/splitlist as UTF-8. Fixes #507962.

2.2.1 bugfix candidate.

Modules/_tkinter.c

@@ -1191,7 +1191,7 @@ Tkapp_SplitList(PyObject *self, PyObject *args)
 	PyObject *v;
 	int i;
 
-	if (!PyArg_ParseTuple(args, "s:splitlist", &list))
+	if (!PyArg_ParseTuple(args, "et:splitlist", "utf-8", &list))
 		return NULL;
 
 	if (Tcl_SplitList(Tkapp_Interp(self), list, &argc, &argv) == TCL_ERROR)
@@ -1219,7 +1219,7 @@ Tkapp_Split(PyObject *self, PyObject *args)
 {
 	char *list;
 
-	if (!PyArg_ParseTuple(args, "s:split", &list))
+	if (!PyArg_ParseTuple(args, "et:split", "utf-8", &list))
 		return NULL;
 	return Split(list);
 }