intricate memory corruption bug prevented me to check the patch
in.  It took me two days to realize why find_state() must do a
double loop over the candidates to check for equality before
checking for inclusion(s).

* iface/gspn/ltlgspn.cc: New options, -e45 and -n.
* iface/gspn/ssp.cc, iface/gspn/ssp.hh: Handle these.
* src/tgbaalgos/gtec/gtec.cc (TRACE): Add some debugging traces.
(couvreur99_check_shy::dump_queue): New function.
* src/tgbaalgos/gtec/gtec.hh (couvreur99_check_shy::dump_queue):
New function.