Metadata handling in README

[ottre]

I think you should note in the README that metadata handling isn't fully implemented. In particular, there's no way to get the URL of the currently playing file.

Please correct me if I'm wrong, once the TrackList interface is added you will be able to get the URL by calling TrackList.GetTracksMetadata.

This is useful info for people who want to communicate with multiple instances of mpv playing videos.

[hoyon]

The MPRIS spec only requires the mpris:id metadata property to be implemented, and any others are up to the implementer to choose.

The URL property was not implemented because there is no easy way to get the URI of the current file with the mpv API, so must be constructed manually. I might give this a go though.

Regarding the TrackList interface, I don't currently intend on implementing this as it would require a lot of extra work, and I'm not sure if anything actually uses it.

[hoyon]

This is my initial attempt at this. It might not work in all cases, so let me know if there are any paths it doesn't work for.

[timakro]

This works nicely with gpodder. Could we get a new release?