In Spotify you can organize playlists into folders, but Mopidy does not support this structure.
Even though MPD does not support playlist folders, our backend API should expose the folder structure, and let it be up to the frontends to either flatten it or show it as is. The MPD frontend could for example prefix playlist names with the playlist's location in the folder hierarchy.
This requires support for playlist folders in pyspotify.
This would be really great for the http-frontend. The list of playlists is too long, and I only have 104...
workaround for mopidy/mopidy#62 - appends folder names to playlist