Removed commented out namespaces.
Added TODO comments noting the feature to be ported.
Ported RegionAdapterBase.SetObservableRegionOnHostingControl method to WinForms.
Replaced linked files with actual files in Prism.WinForms.csproj.
Removed excluded Regions code files from PrismWinForms/Desktop/Prism/Regions/...
Replaced linked files with actual files in Prism.MefExtensions.WinForms.csproj
Removed excluded Regions code files from Prism.MefExtensions.
Replaced linked files with actual files in Prism.Interactivity.
Removed excluded code files from Prism.Interactivity.
Replaced linked files with actual files in Prism.UnityExtensions.
Replaced linked files with actual files in Prism.Mvvm.
Minor changes to align files with original source.