BUGFIX: ActiveMesh::ImportVTK_Ftree() was attempting to

        place offspring at the surface of its mother skeleton.
        The calculation was a) buggy anyway, b) assuming initial segment
        of the offspring reaches out of the mother (so it makes sense
        to make it shorted without "flipping-it-over") -- that was
        not the case in the recent data and so this whole idea was dropped.