bump minimal hets version to revision 18553

Since we now use the --full-theories switch, we
need a hets version which supports it.
fix logic translations question

Both parts of the UNION need to
select logic_ids in order to work properly. So
we shall not pass the ontology.id, but the
ontology.logic_id to the query.
Merge branch '676-translate_sentences' into develop
Merge branch 'develop' into develop.ontohub.org