Bug Fixes in Multimedia
Playlist browser: drag & drop and plugged playlists cleanups
This change fixes a couple of bugs:
* it is now possible to drop tracks & playlists to playlist providers
in Saved Playlists
* When a new empty playlist provider appears or disappears when Amarok is
running, the view is correctly updated.
* "Crop playlist" functionality implemented using drag & drop.
* Drag & drop of tracks and playlists to Saved Playlists works in all cases.
* iPod playlists now appear even when plugged in while Amarok is running.