vtk: update for pugixml-1.11 support
Also comes with:
- OBJ importer vertex color support
- OBJ importer material fixes
- OSPRay rendering leaks
- Rectilinear grid rendering fixes
Cc: @cory.quammen
Backport: release:HEAD^2
Also comes with:
Cc: @cory.quammen
Backport: release:HEAD^2