Bug FIX: cylinders

Latest version of CommbLayer fixes a but that has been around for years(!) Sorry didn't know. If a cylinder is the same as another cylinder, the cylinder is removed from the model. This allows a better OSM (object surface map) in MCNP and other codes.

The test is if two cylinders are nearly equal [i.e. within our rounding variable which is Geomtery::zeroTol [defined in System/geomInc/Vec3d.h] . The test did not work in the case that the Cylinder centres were very close but not actually touching.

[Note that Cylinder== needs to do a projection of the cylinder centres because two cylinders are equal if they have the same primary axis (centre line) and there is a lambda that satisfies C1 + lambda & A == C2 (C1, C2 are the centres and A is the axis which the cylinders share]

The code incorrectly dealt with the case that the cylinder centres were very close. It has been fixed in commit 21e0125.

I would like to suggest that you either merge or cherry pick this commit.