Implementing audio playback, notifications, album art for speaker tapes in Audio fragments

[lschmid83]

The Audio fragments need a lot of work. Currently it displays a list of sources of audio to stream from the web with URL for each speaker tape. I did begin implementing a fragment to play the audio files which is approx. 50% complete but non-functional at the moment. I had problems with the audio notification system and playing audio in the background while the app is not active. If anyone is familiar with streaming audio and the notification system it would be a great help if they could take a look at the code. All of the code for the audio book and speaker tape playback can be found in the ui/audio/ namespace.