Fix 2033 mesh to dt

[akenmorris]

Fix #2033 by using vtkSelectEnclosedPoints to determine if points are inside or outside.

• 2033

Also parallelized mesh to DT, patch bugs in VTK

[akenmorris]

Doesn't matter that is not completely robust. I think it's good enough.

It turns out that it is simply returning a different, but still correct cell. Quite often the closest point on a mesh is at a vertex, and any cell that the vertex belongs to would be valid. The SMP enabled versions can simply turn different cells.