A fix & test for

[ 496873 ] structseqs unpicklable

by adding a __reduce__ method to structseqs.

Will also commit this to the 2.2.1 branch momentarily.
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 1b58edb..e2d2580 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -248,6 +248,13 @@
         b = self.loads(s)
         self.assertEqual(a.__class__, b.__class__)
 
+    def test_structseq(self):
+        import time
+        t = time.localtime()
+        s = self.dumps(t)
+        u = self.loads(s)
+        self.assertEqual(t, u)        
+
 class AbstractPickleModuleTests(unittest.TestCase):
 
     def test_dump_closed_file(self):