void playlist_changed ();
void playlist_content_changed (boost::weak_ptr<Content>, int, bool frequent);
void maybe_add_content (boost::weak_ptr<Job>, boost::weak_ptr<Content>);
void playlist_changed ();
void playlist_content_changed (boost::weak_ptr<Content>, int, bool frequent);
void maybe_add_content (boost::weak_ptr<Job>, boost::weak_ptr<Content>);