Change the PyUnit-based tests to use the test_main() approach.  This
allows using the tests with unittest.py as a script.  The tests will
still run when run as a script themselves.
diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
index 6d9e31d..28d84ce 100644
--- a/Lib/test/test_codecs.py
+++ b/Lib/test/test_codecs.py
@@ -22,4 +22,10 @@
         f = reader(s)
         self.assertEquals(f.read(), u"spamspam")
 
-test_support.run_unittest(UTF16Test)
+
+def test_main():
+    test_support.run_unittest(UTF16Test)
+
+
+if __name__ == "__main__":
+    test_main()