Native binding issue

[Tlaster]

Not sure if we should continue using Windows.UI.Xaml.Data.Binding as native binding implement, there are some limitations:

• Property mapping converter's behavior is slightly different from the Android platform
• Update the value to the view requires DataContext implement System.ComponentModel.INotifyPropertyChanged interface, which JavascriptValue should not implement such interface
  Should we just implement our own binding like the Android platform?