Moved the large cover popup functionality that was found in NowPlaying to CoverInfo (so it is more central), and make all popups of the large cover use this method.

Todo:  Figure out where to make popups appear so that they don't just appear in the top left corner.  I don't know what would be the best place for them to popup - near the mouse cursor? In the center of the screen?  I really don't know.

svn path=/trunk/kdemultimedia/juk/; revision=362333