Ability to "connect" songs in a playlist so they always play together

[beckfield]

I think this is very similar to this suggestion:

Option to use existing m3u for playlist feature

It would be nice to have an option to point Plex to existing m3u playlists and use those for Plex playlists for a DLNA/UPnP music server or serving to Plex clients. Or if not to be used as Plex playlists it could be a separate feature called something like "External Playlists."  Right now I am aware of one piece of software that can make M3u available via UPnP, but I was hoping just to consolidate to use just Plex for all media serving.