BUG:12331 Loosen up tolerance to allow 1e-029.

Per bug report http://www.vtk.org/Bug/view.php?id=12331

Change-Id: Iabd5ab3610ad975043ec6e6e47eecd97871e7d02
Merge topic '0012331-loosen-implicitdataset-evaluarefunction' into master

39c627ea BUG:12331 Loosen up tolerance to allow 1e-029.