Replaced original UnityMVVM folder with movrajr/UnityMVVM, based on MS Reference Sources, adapted for Unity.
Match NotifyCollectionChangedEventHandler signature
Fixed TypeLoadException by replacing lambda with static method.
Fix for "Exception: Can't launch PropertyChanged event. Property 'ScreenPosition' not found in type 'P`1"
Renamed ICommand to IuFrameCommand.
Made IuFrameCommand inherit from System.Windows.Input.ICommand.
Implemented ICommand.CanExecuteChanged.