Various optimisations (seem to break Graphics2D.fill again...)
Revert "Various optimisations (seem to break Graphics2D.fill again...)"

This reverts commit 43318c78ce7e1380f05cd837ef95f91b4678f2f1.
Revert "Revert "Various optimisations (seem to break Graphics2D.fill again...)""

This reverts commit 2f3c56097bd9101e3fcd80997ecc0ec63db41b47.
Fixed the Graphics.fill issue (still don't understand it though...)
The Graphics trick really doesn't wanna work :/
Merged conflicts
jardesc now ASCII instead of MacRoman
Polygon2D: Remove contours with only 3 control points when resampling
* bit of polishing
* feedback forces stabilised a bit more
* Sensitivity parameter back in the block version
* Reduce the stdev for pre-filtering from 1.5 to 1
* Only compute gradient magnitude if edge and region are the same channel AND region info is used
* Set correct Z information on each created contour
* Warn when creating a 2D contour from a ROI with z = -1 in block mode (will use data from z=0 on 3D data)
* some cleaning
* Removed contour_minArea parameter
* New option to output contours as polygons
Volume constraint added to the interface