vtkFiltersOpenTurns module openTURNS version support
This improves the support of different versions of OpenTURNS
in vtkFiltersOpenTurns module, and corrects some bugs.

Adding a cache to the vtkOTScatterPlotMatrix
This commits adds a cache to the vtkOTScatterPlotMatrix for better
reusing of the vtkOTDensityMap filters inside.