It now uses vlc_clone()
It is started only when needed.
It does not uselessly poll every 100 or 10 milliseconds anymore...

Regression introduced by commit 4a590357.

Identity is not a method but a property
"" is not a valid object path

Should close #4810

Close #4798

 * Remove legacy methods
 * Implement the GoTo method

Thanks to j-b and ivoire

really route messages to tracklist interface
fix DBUS_MPRIS_TRACKLIST_INTERFACE definition
fix CanQuit/CanRaise/HasTracklist input types

fix AddTrack function
The function has changed in mpris 2.1, but the additional parameter isn't being used by VLC (yet)

loop/repeat controls are gone, we now need a tri-state button
track change signal doesn't exist anymore in mpris 2.1 and i can't find how
we can be notified of track changes

thanks to mirsal

- exchange U and V plane to get the right colors again
- fixed some compiler warnings about signed - unsigned compare
- and some missing case entries

It also removes useless thread wake up.

Fix #4797