Dialog: reimplemented too much

[Marco Martin]

Hi all,

thinking about what i was needing to reimplement the KRunner shell, I've came 
across a problem that looks too much the problem of the OSD.
We too often need something that is almost identical to Dialog but-not-really 
(because the background is slightly different, because needs some particular 
window flags etc) and is really too tricky to get right (yeah, it "dances" 
again)

So, i came to the conclusion to have its api cleaned up a bit and put it into 
libplasmaquick, so will be possible to have c++ subclasses of it.
So if someone needs a top level window that kinda looks like a frame, there 
will be that possibility available (OSD should totally use that for instance)

Cheers,
Marco Martin