curves widget

[Casper Boemann]

I've just commited a kcurve widget.

It's nicked from digikam, however stripped very much down:

 - There is no histogram showing underneath, to make it generic enough to 
(later) go into kdeui. I will however make it accept a QPixmap as background. 
That way applications (digikam and krita) can put in a histogram.

It's not used anywhere yet, and may even be buggy.
-- 
best regards / venlig hilsen
Casper Boemann.