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_grp.py b/Lib/test/test_grp.py
index 1edb417..a16a922 100755
--- a/Lib/test/test_grp.py
+++ b/Lib/test/test_grp.py
@@ -19,4 +19,9 @@
         entry = grp.getgrnam(self.groups[0][0])
 
 
-test_support.run_unittest(GroupDatabaseTestCase)
+def test_main():
+    test_support.run_unittest(GroupDatabaseTestCase)
+
+
+if __name__ == "__main__":
+    test_main()