anchor.diff:        Verbosity = Verbosity.Normal
         RunnerType = null
         RunnerExtensions = []
  -      Assemblies = [] 
         HintDirectories = [] 
         PluginDirectories = []
         ApplicationBaseDirectory = null
  
positive.code:     param.PluginDirectories |> Seq.iter rtSetup.AddPluginDirectory
      rtSetup
  
  let Run (setParam: GallioParams -> GallioParams) =
      let param = setParam GallioDefaults
      let package = createPackage param
      let project = createProject param package
  
negative.code:       /// extensions to use during the test run.
        /// The value must be in the form '[Namespace.]Type,Assembly[;Parameters]'
        RunnerExtensions: string list // use type + parameters instead of descriptor as string?
        HintDirectories: string seq
        PluginDirectories: string seq 
        ApplicationBaseDirectory: DirectoryInfo
  