Fix for issue #37 - Multiple SetUp Fixtures should be permitted on same ...

This should make it possible to use more than one SetUp fixture per namespace. The order they are executed in is not defined and depends on the implementation of the .NET Framework.

I tested it on Mac OS X with Mono (I think it was Mono 3.8 or 3.10) and on Windows 8.1 with .NET 4.0 and it worked on all of them.

Maybe I'll find a better solution. I will look at this.