Can only have a song once in the queue

[jmorrell]

You can't have multiples of any song in the queue.

This can lead to weird behavior when you say "play this song" when the song is already present in the queue. The current position just jumps back.

Also, saying "play next" will just fail since it won't be added or moved.

[jeffpeterson]

This is intended behavior. I'll open a new issue for moving a song when it already exists in the queue.