[mpris] MPRIS v2.1

[Conor Curran]

Hi Lennart,

> Well, you I don't think it makes sense to focus too narrowly what
> Canonical needs. It doesn't make sense to depart too much from the
> usecase you have, but I'd at least keep things generic enough to be
> useful for more than just a single application.
>
>    
Honestly, I don't really consider what we are asking to be so specific 
that no other potential client will not want to use it. The usecase is 
to be able to query the player for a list of playlists, organise it 
somehow so as the list is not ridiculously big, and then be able to kick 
off a certain playlist.
Seems like a pretty universal need in the greater scheme of remote 
control of music players.

Conor