Fix test_pickle, by reverting the string opcodes (S, T, U) to returning
strings, in Latin-1.  Bytes are once more pickled through bytes.__reduce__,
but now it returns "latin-1" as the second parameter.

Unfortunately this breaks datetime pickling.  I'll have to investigate
further; reverting Martin's changes doesn't seem to help.
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 6340b46..ad5f4fe 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2724,13 +2724,11 @@
 static PyObject *
 bytes_reduce(PyBytesObject *self)
 {
-    /* XXX: This currently returns a Py_UNICODE-widened string
-       in the tuple which is completely useless. Pickle stopped
-       using it for that reason. */
-    return Py_BuildValue("(O(s#))",
+    return Py_BuildValue("(O(s#s))",
                          self->ob_type,
                          self->ob_bytes == NULL ? "" : self->ob_bytes,
-                         self->ob_size);
+                         self->ob_size,
+                         "latin-1");
 }
 
 static PySequenceMethods bytes_as_sequence = {