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_xmllib.py b/Lib/test/test_xmllib.py
index a1c5057..9ea5042 100644
--- a/Lib/test/test_xmllib.py
+++ b/Lib/test/test_xmllib.py
@@ -27,4 +27,9 @@
         parser.close()
 
 
-test_support.run_unittest(XMLParserTestCase)
+def test_main():
+    test_support.run_unittest(XMLParserTestCase)
+
+
+if __name__ == "__main__":
+    test_main()