further improved fine point w.r.t. replaying in the presence of chained facts and a non-empty meta-quantifier prefix + avoid printing internal names in backquotes

added "!=" (disequality) as a TPTP binary operator, since it pops up in LEO-II proofs

merged

tuned signature;

produce nodes_status outside GUI thread, to avoid a few milliseconds of blocking;

avoid too aggressive optimization of 'finite' predicate

avoid unsound simplification of (C (s x)) when s is a selector but not C's

extended theory exporter to also export MePo-selected facts