Add notifications for play/pause/stop

[tkowalczyk]

As all of the Android applications have them

[tkowalczyk]

https://blog.xamarin.com/background-audio-streaming-with-xamarin-android/

[freud]

Yes, this functionality is similar to something I've expected in a first contact with the app.

Going to recently played episode would be great and for me it would be even in the application main menu. I've looked for this in a first contact with the app.