patch for test localization issue in C#

Some localized computers fail the C# test suite because the ArrayList implementation uses a different string compare for sorting than the trees do.

Try adding this at the beginning of the test Main() method

Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.InvariantCulture;

to fix the problem. (This will be in the next release, but didn't merit a release by itself).