Save scrobbling queue
If a track has failed to be scrobbled, it should be saved to be scrobbled later.
According to official documentation ( http://www.audioscrobbler.net/development/protocol/ ):
Clients should be able to cope with long (multiples hours) downtime from the server. This may be caused by either server failure or a lack of network connectivity by the client (e.g. a portable system such as a laptop with only brief connectivity).
Seems like the best way to do this is to use
Track::toDomElement() to save tracks and to use the
Track (QDomElement) ctor to restore them later on.
Keep in mind that the queue must survive between LC's restarts.