Official NUnit Release

I have just uploaded a version of TestDriven.NET that was built against the latest official NUnit release (2.2.6). From now on I'll only be using official NUnit releases rather than doing continuous integration using the latest NUnit source in CVS. There was some method to my madness when I started doing continuous integration with the NUnit source. However now the NUnit feature I needed is part of the official release, there is no longer an imperative to stay on the bleeding edge. This should make for more stable releases and fewer surprises for Charlie Poole and the NUnit team.