[collected] Support for external playlist

Hi,

I am using volumio in a raspberry pi and it is awsome.
I would like volumio could play external playlist. I have a lot of m3u playlist with music storaged on a nas. It would be great can configure a folder with these external playlist and volumio can play those playlist that have tracks on a nas.

The playlist have full shared folder like ‘192.168.1.12/Music/Album/Track01.mp3’

Thanks.