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_pkgimport.py b/Lib/test/test_pkgimport.py
index 2f19509..72889f9 100644
--- a/Lib/test/test_pkgimport.py
+++ b/Lib/test/test_pkgimport.py
@@ -75,4 +75,10 @@
         reload(module)
         self.assertEqual(getattr(module, var), 1)
 
-run_unittest(TestImport)
+
+def test_main():
+    run_unittest(TestImport)
+
+
+if __name__ == "__main__":
+    test_main()