1) I modified the contour filter so that you could specify which variable in
   the vtkmDataSet to contour by. I also modified the filter to add the 
   field being contoured to the output vtkmDataSet to match the VTK behavior.

2) I modified the VTKm to VTK conversion to also convert fields from VTKm
   to VTK.



git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@27933 18c085ea-50e0-402c-830e-de6fd14e8384