Make sure no two AMinor geometries for the same elements are stored.
Make sure no two AMinor geometries for the same elements are stored.

This commit should be unneccessary, because for any given elements, the
orientation is deterministically calculated.
However, we never know what floating point arithmetic does, so this new class is an
additional security measure.

pkerpedjiev/ernwin,pkerpedjiev/ernwin,pkerpedjiev/ernwin,pkerpedjiev/ernwin