Allow to play songs from a specific author

[teknoraver]

When searching for an artist, DSub will present a list of albums which contains at least a song by that artist. And when playing one, the full album is played.

It would be nice if the play button on top of the search results, would play only the songs of such artist, as ampache does when search for an artist via a call to /ajax.server.php?page=stream&action=directplay&object_type=artist&object_id=1717 or /stream.php?action=play_item&object_type=artist&object_id=1717

This happes when you have some collection albums where any song is from a different artist.