* app/Makefile.am: added gimphistogram*, histogramwidget*,
removed histogram.[ch]
* app/histogram.[ch]: removed. replaced with histogramwidget.[ch].
* app/{gimphistogramP.h, gimphistogram.h, gimphistogram.c}: new
functions that calculate histograms in parallel and perform
calculations on them.
* app/histogramwidget.[ch]: Same as old histogram.[ch], only it is
now a real widget, and it uses GimpHistograms instead of arrays of
values.
* app/curves.c: #include gimphistogram.h instead of histogram.h.
* app/equalize.c: use GimpHistogram and GimpLut.
* app/gimpbrush.c, app/gimpimage.c, app/gimpset.c: use
GTK_RUN_FIRST in calls to gimp_signal_new.
* app/histogram_tool.c, app/levels.c, app/threshold.c: modified to
use the new HistogramWidget.
* app/paint_funcs.c: removed some unused variables.
* app/preferences_dialog.c: only display the num-processor field
if we are configured --with-mp
* plug-ins/gee/gee.c: removed a couple of c++ style comments.
jaycox