RFC: Refactor CD player logic from kscd

[Shaheed]

Michael wrote:
> 
> > 1. There should be a common definition of the (default) CD playback 
device.
> > At this point, I propose not to worry about multiple devices. [shared by
> > kscd, kaudiocreator at least].
> 
> I don't like that. I hate having to remember which of my CD drives is the 
one
> I can use to play CDs in. audiocd:/ autodetects which one has the CD in,
> which is very nice.
> >

Oh, I was not clear enough. I will keep audiocd: - in fact it should be the 
new default.