Turn off/catch VTK debug statements

[durack1]

@doutriaux1 @danlipsa FYI, with missing (no data) I am getting the following error:

Warning: In /export/doutriaux1/anaconda2/conda-bld/vtk-cdat_1479229648549/work/Filters/Geometry/vtkDataSetSurfaceFilter.cxx, line 166
vtkDataSetSurfaceFilter (0x3043b80): Number of cells is zero, no data to process.

For the release it would be great to turn these useless debug statements off (as they are pointing to the conda-bld directory, and have nothing to do with the local conda-installed environment), or even better catch them with a better, more meaningful warning for users.

The path above does nothing more to confuse the hell out of people, as /export/doutriaux1/.. is very unlikely going to exist on their systems