Revert "Combination of VTK_USE_X and VTK_USE_OSMESA possible"
Revert "Combination of VTK_USE_X and VTK_USE_OSMESA possible"

This reverts commit d6fb76e4c0a4bdb6356ad9aa4dcfc45fc0ac58da.

SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,keithroe/vtkoptix,SimVascular/VTK,keithroe/vtkoptix,SimVascular/VTK,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,SimVascular/VTK