* New: In CRL::GdsStream::xyToPath(), now manage BGNEXTN & ENDEXTN for
    PATHTYPE 4.
      The begin/end Contact are created to use exactly the area of the
    extension. Otherwise there were overspill when the size of the
    extension is greater than the width of the path. Also need to do
    a sligth shift if the extension is an odd number of foundry grid.
      This fix the offgrid problems.