CAD11 — CadBrep::OrientedEdge interface issue

The CadBrep::OrientedEdge interface has two very similar methods to get the Face/OrientedFace which uses the OrientedEdge. That's pretty redundant. Besides: Both methods deliver useful information only when the OrientedEdge belongs to one and only one Face. Otherwise an exception is generated. I don't really see the usefulness of those two method, especially since for many cases there are two Faces for the Edge and one can always traverse there via the EdgeLoop.