[Snails] Return QList from LoadIDs().
[Snails] Pass the ID to sync from to ATW::synchronize().
[Snails] Refactored messages getting into GetMessagesInFolder().
[LMP] FindAlbumArt() now templated.
[LMP] Use QImage internally for AlbumArt fetching.
[Util] Virtual base dtor for SlotClosure.
[Util] Better code.
[Util] Publicly derive from FireDestrPolicy.
[LMP] Load album art lazily and in a separate thread.
[LMP] Maintain a set of items in playlist.

Speeds up adding new items to playlist & loading linearly and a lot.