And finally part three in the histogram redesign. Group the results of histogram calculations in a single class, and calculate some results. Too bad that you can notice some numerical instability in the calculations as opposed to calculating it colorspace dependent...
This also introduces another feature: a selection on a histogram. It could be possible that the user selects a region on the histogram, and then seperate calculations are displayed. The drawing code already supports this, but it can not yet be accessed by the GUI (although it probably shouldn't be too hard for someone with more gui Qt knowledge).
Also fixes a bug where the displayed histograms didn't match their names with RGBA.

svn path=/trunk/koffice/; revision=460023