Simplified Overlay code (manual "cherry pick" from the master branch)
* MAJOR update: 3D processing is now functional! (JarDesc adjusted accordingly)
* ActiveContour & sub-classes: the main plugin class needs not be referenced anymore
* Multi-thread services improved (were creating immortal threads...)
* Made some fields public (manual "cherry pick" from the current master branch
* Adjusted the image pre-processing steps
* ReSampler now indicates if a contour has vanished or divided
* ROI output now requires a sequence to check for the pixel size (for 3D)
MagicWand2D moved to main package (operational, but still not released, perhaps as an independent plugin ?)