Allowing playlist to be edited by others.

[dutchcomputerkid]

It would be nice to be able to create playlists everyone can contribute on. As my server shares many users, it is sometimes nice to be able to edit playlists together. Now, they'll have to constantly add requests to the playlist's creator instead of being able to do it themselves.

So tl;dr: multi-user editable playlists would really help with keeping 'work' down and fun high