[amarok] src: Remove unused AudioCdTrackProvider

[Matěj Laitl]

On 18. 2. 2013 Bart Cerneels wrote:
> On Sun, Feb 17, 2013 at 6:39 PM, Matěj Laitl <matej at laitl.cz> wrote:
> > Git commit d6251e08012056b1e3920edb7ae2d451bcdf9218 by Matěj Laitl.
> > 
> > Remove unused AudioCdTrackProvider
> 
> Wasn't this part of AudioCdCollection? How did that ever work?

AudioCdCollection is a TrackProvider itself (through Collections::Collection) 
and has its own implementation of possiblyContainsTrack() and trackForUrl().

AudioCdTrackProvider was simply a historic remnant or a thing implemented but 
never actually used. (unfortunately we have more of these) The class simply 
wasn't instantiated anywhere in Amarok code.

	Matěj