ENH: Added option to use TBB as SMP backend in VTK
It significantly improves vtk speed (typically by 20-30%, in some situations by a factor of 10x or more).
The change has been tested on Windows (building, running, packaging).
Linux build may need a patch (see TODO:) and Mac build may need some work with rpaths.
To test: when configuring Slicer build, set Slicer_VTK_SMP_IMPLEMENTATION_TYPE
CMake variable to TBB
.
This is a follow-up of https://github.com/Slicer/Slicer/pull/930 (probably this will make that pull request obsolete).