Add reference application for streaming

[postlund]

What feature would you like? A simple application called atvstream that is more flexible when it comes to streaming (mainly audio) to a receiver. One use case is providing a directory of files that are all streamed one after another.

Describe the solution you'd like For now, just accept RAOP credentials and a target (similar to atvremote and atvscript) and a files, glob or directory to play:

$ atvstream -s 10.0.0.5 --raop-credentials xxx --recursive file.mp3 /music more/*.flac

Any other information to share? Some other features for the future:

• Next and previous
• Repeat and shuffle
• Artwork through 3rd party library
• Media controls via CLI