WPI: filter unique itersection points using some small comparison tolerance
WPI: filter unique itersection points using some small comparison tolerance

Use floating point tolerance to compare MD values of intersection
points, i.e. all points are considered the same in bounds [MD-tol, MD+tol].

Fix bug when visually duplicating points (actually they differ by very
little bit beyond tolerance) apper in intersection results.

bs-eagle/bs-eagle,bs-eagle/bs-eagle,bs-eagle/bs-eagle