block 640511 by 640662
block 640511 by 640522
In order to build VolView we either need an old VTKEdge built against
VTK 5.4, or a VTKEdge after the switch 5.4 -> 5.6. vtkKWEVolumeMapper
was renamed into vtkSmartVolumeMapper in VTK 5.8 and later.
Since VolView will be entering unstable, and VTK 5.8.0 is just out, I
believe this is easier to simply make VolView B-D on libvtk5-dev >=
5.8.0 and appropriate vtkedge version.
kwwidgets will need to be rebuild against VTK 5.8 at that point, which
should hopefully hide symptoms from 640522