Merge branch 'bug-8078-imagestatistics-planarfigure-offset'
- bug-8078-imagestatistics-planarfigure-offset: introduced new pipeline to create imagemask from PlanarFigure; Build a switch to use two VTK 5.8 classes even when using VTK 5.6 (with VTK 5.8, use the real VTK classes) adding classes from VKT 5.8 needed for statistics calculation