Add Jukebox mode (subsonic API feature)

[niawag]

Hi and congrats for this great app, I love it's design and, even if I did not used it much it seems rock solid!

I may have a niche case (not sure it's niche though) but I really like the fact that subsonic API allows to either stream to phone or play directly on the server so I can use the same app to play music on the road or at home. DSub (client side) and some great subsonic API implementations (as gonic, supysonic or navidrome - server-side) have this feature.

Do you plan on implementing the jukebox mode in your app ? The REST API doc concerning this feature is there: http://www.subsonic.org/pages/api.jsp#jukeboxControl
If you plan to go this way I'll be glad to test it on my setting (selfhosted gonic instance)

Keep up the good work !