bug: Live playlist does not update when other clients modify it, until you refresh

[5HT2]

If another client modifies the live playlist, you have to refresh the page in order to view the new changes.

Also, it is not clear to the user if the live playlist has been changed until you do so, meaning if someone else adds something, you have no way of knowing if you have to refresh or not.

This wouldn't be solved by #434, but is somewhat related.

[5HT2]

Okay, it looks like the live player is also unaware of new changes when going to play the next track, and this is not just a visual bug.

This means that unless you refresh, new songs being added by another client will not actually do anything effectively.

As a result of refreshing killing the current Jukebox session and generating a new token (which would also be solved by #434), this makes it impossible to modify the live playlist outside of the remote controller page, currently, which does not have the ability to remove tracks or rearrange them.