Added methods to retrieve the accumulated and normalized accumulated
histograms.
Added a dialog to view the image LUT
Fixed a typo in dRGBHistogramValue.
Fixed the grayscale histogram
Added linear equalization.

Fixed potential problems in the cumulative and normalized vectors in
ImgManip::Histogram.
Added color inversion for indexed grayscale images.
LUTDialog has been modified to display an arbitrary LUT.
Added a method Manipulator::lut() to retrieve the color table.
Added Histogram::matchPiecewiseHistogram.

Reformat of all the project files. No changes.
Added piecewise matching
Implemented gamma correction.

Implemented histogram matching. Not used nor tested.
Implemented nearest-neighbour interpolated scaling.