Add support for new "last loaded playlist" mpd feature

[r3d4]

Upcoming mpd supports to remember and show the last loaded playlist.
It would be great if this would be accessible in mpc.
See: MusicPlayerDaemon/MPD@bfbff31

[incogninto1-1]

Hello. Sorry for the out of context posting, however would you mind sending me some contact information. I wanted to talk about one of your older projects if you don't mind