So that its run time goes from 10min+ to ~5s.

* src/tgbatest/emptchk.cc: New file.
* src/tgbatest/Makefile.am: Add it.
* src/tgbatest/emptchk.test: Use it.

Again instead of calling ltl2tgba dozen of times with different options
for various formulas, this implements a single executable that reads
formulas from a file, translate them using the different setups, and
dump statistics for comparison.  Valgrind now only has to be started
once.

* src/tgbatest/checkta.cc: New file.
* src/tgbatest/Makefile.am: Use it.
* src/tgbatest/ltl2ta.test: Rewrite using checkta.
* src/tgbatest/ltl2tgba.cc: Remove a unused variable.

So that running valgrind is a lot more efficient.  Running
ltl2tgba.test using to take more than 15min.  We are now down to
25sec.

* src/tgbatest/checkpsl.cc: New file.
* src/tgbatest/Makefile.am: Add it.
* src/tgbatest/ltl2tgba.test: Adjust.

This generalizes the previous patch.

* src/ltltest/equalsf.cc: Allow escaped '\,' and
negated result.
* src/ltltest/Makefile.am: Use equalsf.cc for
almost all tests that used equals.cc.
(nequals): New.
* src/ltltest/equals.test, src/ltltest/eventuniv.test,
src/ltltest/lunabbrev.test, src/ltltest/nenoform.test,
src/ltltest/parseerr.test, src/ltltest/tunabbrev.test,
src/ltltest/tunenoform.test: Adjust.

This test used to take more than 10min because an instance of valgrind
was launched for each separate equivalence check.  The list of
equivalences to checks are not given in a file, and only two valgrind
instances are run.  The test takes less than 15sec.

* src/ltltest/equalsf.cc: New file.
* src/ltltest/Makefile.am (reduccmp, reductaustr): Build using
equalsf.cc.
* src/ltltest/reduccmp.test: Rewrite.
* src/ltltest/uwrm.test: Also rewrite, and use valgrind.

* src/tgba/tgbagraph.hh: Remove the set_bprop/get_bprop interface.
* src/tgba/tgba.cc, src/tgba/tgba.hh: Add a new interface for
setting/querying/copying the following properties: single_acc_set,
state_based_acc, inherently_weak, deterministic.
* src/dstarparse/dra2ba.cc, src/dstarparse/nra2nba.cc,
src/neverparse/neverclaimparse.yy, src/saba/sabacomplementtgba.cc,
src/tgba/tgbagraph.cc, src/tgbaalgos/degen.cc, src/tgbaalgos/dotty.cc,
src/tgbaalgos/isdet.cc, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/postproc.cc, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/simulation.cc, src/tgbatest/degenlskip.test,
src/tgbatest/ltl2tgba.cc: Adjust to the new interface, or use
it to bypass some useless work.

* src/tgbaalgos/degen.cc (degeneralize, degeneralize_tba): Shortcut
degeneralization if the automaton is already degeneralized.

* iface/dve2/dve2.cc, iface/dve2/dve2.hh,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/ltlvisit/contain.cc, src/ltlvisit/contain.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh,
src/tgba/bddprint.cc, src/tgba/bddprint.hh, src/tgba/formula2bdd.cc,
src/tgba/formula2bdd.hh, src/tgba/taatgba.cc, src/tgba/taatgba.hh,
src/tgba/tgbagraph.hh, src/tgbaalgos/compsusp.cc,
src/tgbaalgos/compsusp.hh, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/lbtt.hh, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_fm.hh, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/randomgraph.hh, src/tgbaalgos/translate.cc,
src/tgbaalgos/translate.hh, src/tgbaalgos/word.cc,
src/tgbaalgos/word.hh: Pass shared_ptr to functions by const ref.

A type such as 'const tgba_digraph*' and 'tgba_digraph*' are replaced
by 'const_tgba_digraph_ptr' and 'tgba_digraph_ptr'.  Additionally 'new
tgba_digraph(...)' is replaced by 'make_tgba_digraph(...)'.

This convention is followed by all automata types. Those smart
pointers should normally be passed by const reference as input of
function to avoid the atomic increments/decrements, but I probably
missed a few, as this huge patch took me nearly 12h.

* src/kripke/fwd.hh, src/tgba/fwd.hh: New files.
* src/kripke/Makefile.am, src/tgba/Makefile.am: Adjust.
* iface/dve2/dve2.cc, iface/dve2/dve2.hh, iface/dve2/dve2check.cc,
src/bin/common_output.hh, src/bin/dstar2tgba.cc,
src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc, src/bin/ltlcross.cc,
src/bin/ltlfilt.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/dstar2tgba.cc, src/dstarparse/dstarparse.yy,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc,
src/dstarparse/public.hh, src/graphtest/tgbagraph.cc,
src/kripke/fairkripke.hh, src/kripke/kripke.hh,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/kripke/kripkeprint.cc, src/kripke/kripkeprint.hh,
src/kripkeparse/kripkeparse.yy, src/kripkeparse/public.hh,
src/kripketest/parse_print_test.cc, src/ltlvisit/apcollect.cc,
src/ltlvisit/apcollect.hh, src/ltlvisit/contain.cc,
src/ltlvisit/contain.hh, src/neverparse/neverclaimparse.yy,
src/neverparse/public.hh, src/priv/accmap.hh,
src/priv/countstates.cc, src/priv/countstates.hh, src/saba/saba.hh,
src/saba/sabacomplementtgba.cc, src/saba/sabacomplementtgba.hh,
src/sabaalgos/sabadotty.cc, src/sabaalgos/sabadotty.hh,
src/sabaalgos/sabareachiter.cc, src/sabaalgos/sabareachiter.hh,
src/sabatest/sabacomplementtgba.cc, src/ta/ta.hh,
src/ta/taexplicit.cc, src/ta/taexplicit.hh, src/ta/taproduct.cc,
src/ta/taproduct.hh, src/ta/tgta.hh, src/ta/tgtaexplicit.cc,
src/ta/tgtaexplicit.hh, src/ta/tgtaproduct.cc,
src/ta/tgtaproduct.hh, src/taalgos/dotty.cc, src/taalgos/dotty.hh,
src/taalgos/emptinessta.cc, src/taalgos/emptinessta.hh,
src/taalgos/minimize.cc, src/taalgos/minimize.hh,
src/taalgos/reachiter.cc, src/taalgos/reachiter.hh,
src/taalgos/statessetbuilder.cc, src/taalgos/statessetbuilder.hh,
src/taalgos/stats.cc, src/taalgos/stats.hh, src/taalgos/tgba2ta.cc,
src/taalgos/tgba2ta.hh, src/tgba/bdddict.cc, src/tgba/bdddict.hh,
src/tgba/formula2bdd.hh, src/tgba/futurecondcol.cc,
src/tgba/futurecondcol.hh, src/tgba/taatgba.hh, src/tgba/tgba.cc,
src/tgba/tgba.hh, src/tgba/tgbagraph.hh,
src/tgba/tgbakvcomplement.cc, src/tgba/tgbakvcomplement.hh,
src/tgba/tgbamask.cc, src/tgba/tgbamask.hh, src/tgba/tgbaproduct.cc,
src/tgba/tgbaproduct.hh, src/tgba/tgbaproxy.cc,
src/tgba/tgbaproxy.hh, src/tgba/tgbasafracomplement.cc,
src/tgba/tgbasafracomplement.hh, src/tgba/tgbascc.cc,
src/tgba/tgbascc.hh, src/tgba/tgbasgba.cc, src/tgba/tgbasgba.hh,
src/tgba/wdbacomp.cc, src/tgba/wdbacomp.hh,
src/tgbaalgos/bfssteps.cc, src/tgbaalgos/bfssteps.hh,
src/tgbaalgos/complete.cc, src/tgbaalgos/complete.hh,
src/tgbaalgos/compsusp.cc, src/tgbaalgos/compsusp.hh,
src/tgbaalgos/cycles.hh, src/tgbaalgos/degen.cc,
src/tgbaalgos/degen.hh, src/tgbaalgos/dotty.cc,
src/tgbaalgos/dotty.hh, src/tgbaalgos/dottydec.cc,
src/tgbaalgos/dottydec.hh, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtbasat.hh, src/tgbaalgos/dtgbacomp.cc,
src/tgbaalgos/dtgbacomp.hh, src/tgbaalgos/dtgbasat.cc,
src/tgbaalgos/dtgbasat.hh, src/tgbaalgos/dupexp.cc,
src/tgbaalgos/dupexp.hh, src/tgbaalgos/emptiness.cc,
src/tgbaalgos/emptiness.hh, src/tgbaalgos/gtec/gtec.cc,
src/tgbaalgos/gtec/gtec.hh, src/tgbaalgos/gtec/status.cc,
src/tgbaalgos/gtec/status.hh, src/tgbaalgos/gv04.cc,
src/tgbaalgos/gv04.hh, src/tgbaalgos/isdet.cc,
src/tgbaalgos/isdet.hh, src/tgbaalgos/isweakscc.cc,
src/tgbaalgos/lbtt.cc, src/tgbaalgos/lbtt.hh,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2taa.hh,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_fm.hh,
src/tgbaalgos/magic.cc, src/tgbaalgos/magic.hh,
src/tgbaalgos/minimize.cc, src/tgbaalgos/minimize.hh,
src/tgbaalgos/ndfs_result.hxx, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/neverclaim.hh, src/tgbaalgos/postproc.cc,
src/tgbaalgos/postproc.hh, src/tgbaalgos/powerset.cc,
src/tgbaalgos/powerset.hh, src/tgbaalgos/projrun.cc,
src/tgbaalgos/projrun.hh, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/randomgraph.hh, src/tgbaalgos/reachiter.cc,
src/tgbaalgos/reachiter.hh, src/tgbaalgos/reducerun.cc,
src/tgbaalgos/reducerun.hh, src/tgbaalgos/replayrun.cc,
src/tgbaalgos/replayrun.hh, src/tgbaalgos/rundotdec.cc,
src/tgbaalgos/rundotdec.hh, src/tgbaalgos/safety.cc,
src/tgbaalgos/safety.hh, src/tgbaalgos/save.cc,
src/tgbaalgos/save.hh, src/tgbaalgos/scc.cc, src/tgbaalgos/scc.hh,
src/tgbaalgos/sccfilter.cc, src/tgbaalgos/sccfilter.hh,
src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh,
src/tgbaalgos/se05.cc, src/tgbaalgos/se05.hh,
src/tgbaalgos/simulation.cc, src/tgbaalgos/simulation.hh,
src/tgbaalgos/stats.cc, src/tgbaalgos/stats.hh,
src/tgbaalgos/stripacc.cc, src/tgbaalgos/stripacc.hh,
src/tgbaalgos/tau03.cc, src/tgbaalgos/tau03.hh,
src/tgbaalgos/tau03opt.cc, src/tgbaalgos/tau03opt.hh,
src/tgbaalgos/translate.cc, src/tgbaalgos/translate.hh,
src/tgbaparse/public.hh, src/tgbaparse/tgbaparse.yy,
src/tgbatest/complementation.cc, src/tgbatest/explprod.cc,
src/tgbatest/ltl2tgba.cc, src/tgbatest/ltlprod.cc,
src/tgbatest/maskacc.cc, src/tgbatest/powerset.cc,
src/tgbatest/randtgba.cc, src/tgbatest/taatgba.cc,
src/tgbatest/tgbaread.cc, src/tgbatest/tripprod.cc,
wrap/python/ajax/spot.in, wrap/python/spot.i,
wrap/python/tests/interdep.py: Use shared pointers for automata.

* src/tgba/tgbaunion.cc, src/tgba/tgbaunion.hh: Delete.
* src/tgba/Makefile.am: Adjust.

* src/tgba/bdddict.hh (bdd_dict_ptr): New type.
(make_bdd_dict): New function.
* iface/dve2/dve2.cc, iface/dve2/dve2.hh, iface/dve2/dve2check.cc,
src/bin/dstar2tgba.cc, src/bin/ltlcross.cc,
src/dstarparse/dstarparse.yy, src/dstarparse/public.hh,
src/graphtest/tgbagraph.cc, src/kripke/kripkeexplicit.cc,
src/kripke/kripkeexplicit.hh, src/kripke/kripkeprint.cc,
src/kripkeparse/kripkeparse.yy, src/kripkeparse/public.hh,
src/kripketest/parse_print_test.cc, src/ltlvisit/apcollect.cc,
src/ltlvisit/contain.cc, src/ltlvisit/contain.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh,
src/neverparse/neverclaimparse.yy, src/neverparse/public.hh,
src/priv/accmap.hh, src/saba/saba.hh, src/saba/sabacomplementtgba.cc,
src/saba/sabacomplementtgba.hh, src/sabatest/sabacomplementtgba.cc,
src/ta/ta.hh, src/ta/taexplicit.cc, src/ta/taexplicit.hh,
src/ta/taproduct.cc, src/ta/taproduct.hh, src/ta/tgtaexplicit.cc,
src/ta/tgtaexplicit.hh, src/taalgos/dotty.cc, src/tgba/bddprint.cc,
src/tgba/bddprint.hh, src/tgba/formula2bdd.cc, src/tgba/formula2bdd.hh,
src/tgba/taatgba.cc, src/tgba/taatgba.hh, src/tgba/tgba.hh,
src/tgba/tgbagraph.hh, src/tgba/tgbakvcomplement.cc,
src/tgba/tgbakvcomplement.hh, src/tgba/tgbaproduct.cc,
src/tgba/tgbaproduct.hh, src/tgba/tgbaproxy.cc, src/tgba/tgbaproxy.hh,
src/tgba/tgbasafracomplement.cc, src/tgba/tgbasafracomplement.hh,
src/tgba/tgbascc.cc, src/tgba/tgbascc.hh, src/tgba/tgbasgba.cc,
src/tgba/tgbasgba.hh, src/tgba/tgbaunion.cc, src/tgba/tgbaunion.hh,
src/tgba/wdbacomp.cc, src/tgbaalgos/compsusp.cc,
src/tgbaalgos/compsusp.hh, src/tgbaalgos/degen.cc,
src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc,
src/tgbaalgos/emptiness.cc, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/lbtt.hh, src/tgbaalgos/ltl2taa.cc,
src/tgbaalgos/ltl2taa.hh, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_fm.hh, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/randomgraph.hh, src/tgbaalgos/save.cc,
src/tgbaalgos/translate.cc, src/tgbaalgos/translate.hh,
src/tgbaalgos/word.cc, src/tgbaalgos/word.hh, src/tgbaparse/public.hh,
src/tgbaparse/tgbaparse.yy, src/tgbatest/complementation.cc,
src/tgbatest/explprod.cc, src/tgbatest/ltl2tgba.cc,
src/tgbatest/ltlprod.cc, src/tgbatest/maskacc.cc,
src/tgbatest/powerset.cc, src/tgbatest/randtgba.cc,
src/tgbatest/taatgba.cc, src/tgbatest/tgbaread.cc,
src/tgbatest/tripprod.cc, wrap/python/ajax/spot.in,
wrap/python/tests/alarm.py, wrap/python/tests/ltl2tgba.py,
wrap/python/tests/parsetgba.py: Update to use bdd_dict_ptr and
make_bdd_dict().

* src/tgba/bdddict.cc, src/tgba/bdddict.hh
(register_all_propositions_of): New method.
* src/tgba/tgbagraph.hh (copy_ap_of): New method.
* src/dstarparse/dra2ba.cc, src/dstarparse/nra2nba.cc,
src/dstarparse/nsa2tgba.cc, src/tgbaalgos/degen.cc,
src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc,
src/tgbaalgos/dupexp.cc, src/tgbaalgos/emptiness.cc,
src/tgbaalgos/minimize.cc, src/tgbaalgos/powerset.cc,
src/tgbaalgos/sccfilter.cc, src/tgbaalgos/simulation.cc,
src/tgbaalgos/stripacc.cc: Simplify using copy_ap_of.

* src/tgba/tgbagraph.cc: New file.
* src/tgba/Makefile.am: Adjust.
* src/tgba/tgbagraph.hh (set_single_acceptance_set,
new_acc_transition): New methods.
(set_acceptance_conditions, merge_transitions): Move body
to tgbagraph.cc.
* src/tgbaalgos/complete.cc, src/tgbaalgos/degen.cc,
src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbacomp.cc,
src/neverparse/neverclaimparse.yy, src/dstarparse/dra2ba.cc,
src/dstarparse/nra2nba.cc: Simplify using these new methods.

Replace it by a new degeneralize_tba(), that use the same tricks as
degeneralize().

* src/tgba/tgbatba.cc, src/tgba/tgbatba.hh: Delete.
* src/tgba/Makefile.am: Adjust.
* src/tgbaalgos/degen.cc, src/tgbaalgos/degen.hh: Implement
a degeneralize_tba() function sharing its code
with degeneralize().
* src/tgbatest/ltl2tgba.cc: Rename -D to -DT so that we can pass it the
same option as -DS.
* src/tgbatest/degenid.test, src/tgbatest/emptchk.test,
src/tgbatest/emptchke.test, src/tgbatest/ltlcounter.test,
src/tgbatest/ltlcross.test, src/tgbatest/spotlbtt.test,
src/tgbatest/ltl2tgba.test: Adjust.
* src/tgbatest/det.test, src/tgbatest/emptchk.test: Adjust numbers to
the smaller output.
* src/saba/sabacomplementtgba.cc, src/saba/sabacomplementtgba.hh,
src/tgbaalgos/minimize.cc, src/tgbaalgos/neverclaim.cc,
src/tgbaalgos/neverclaim.hh, src/tgbaalgos/postproc.cc,
src/tgbatest/randtgba.cc, src/tgbatest/complementation.cc,
wrap/python/spot.i, wrap/python/tests/ltl2tgba.py,
src/sabatest/sabacomplementtgba.cc: Adjust to the removal
of tgba_tba_proxy, using degeneralize_tba() if needed.

* src/tgba/tgbagraph.hh: Automatize the setting of the SingleAccSet
property.
* src/tgbaalgos/minimize.cc: Do not bother setting SingleAccSet.
* src/tgba/sba.hh: Delete.
* src/tgba/Makefile.am, wrap/python/spot.i: Adjust.
* src/taalgos/tgba2ta.cc: Do not include sba.hh.
* src/neverparse/neverclaimparse.yy: Set the SBA property on the output.
* src/tgbaalgos/lbtt.cc (lbtt_read_gba): Set the StateBasedAcc property
on output.
* src/tgbaalgos/dotty.cc, src/tgbaalgos/neverclaim.cc: Do not rely on
the sba interface.
* src/dstarparse/dra2ba.cc, src/dstarparse/nra2nba.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/sccfilter.cc: Set
tgba_digraph::StateBasedAcc as appropriate.
* src/tgbatest/ltl2tgba.cc: Add extra assert.

* src/saba/sabacomplementtgba.cc, src/saba/sabacomplementtgba.hh,
src/tgba/tgbatba.cc, src/tgba/tgbatba.hh, src/tgbaalgos/degen.hh,
src/tgbatest/complementation.cc, src/tgbatest/ltl2tgba.cc: Here.

* src/ltlvisit/destroy.cc, src/ltlvisit/destroy.hh,
src/ltlvisit/reduce.cc, src/ltlvisit/reduce.hh: Delete.
* src/ltlvisit/Makefile.am: Adjust.
* src/ltlvisit/clone.cc, src/ltlvisit/clone.hh (clone): Remove.
* src/ltlvisit/contain.hh (reduce_tau03): Remove.

* src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh: Delete.
* src/tgba/Makefile.am: Adjust.
* src/tgbaalgos/reductgba_sim.cc, src/tgbaalgos/reductgba_sim.hh:
Delete these obsoleted algorithms.
* src/tgbaalgos/Makefile.am: Adjust.
* src/tgbatest/explicit.cc, src/tgbatest/explicit.test,
src/tgbatest/explicit2.cc, src/tgbatest/explicit2.test,
src/tgbatest/explicit3.cc, src/tgbatest/explicit3.test:
Delete.
* src/tgbatest/Makefile.am: Adjust.
* src/bin/ltl2tgba.cc, src/priv/countstates.cc,
src/tgbaalgos/isweakscc.cc, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/minimize.cc,
src/tgbaalgos/minimize.hh, src/tgbaalgos/powerset.cc,
src/tgbaalgos/powerset.hh, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/sccfilter.hh, src/tgbaalgos/simulation.cc,
src/tgbatest/explprod.cc, src/tgbatest/ltl2tgba.cc,
src/tgbatest/powerset.cc, src/tgbatest/tgbaread.cc,
src/tgbatest/tripprod.cc, wrap/python/ajax/spot.in,
wrap/python/spot.i: Remove all remaining references to
tgba_explicit.

This is a huge patch.  tgba_digraph are equiped with some boolean
properties that can be used to indicate whether they represent SBA
(and will carry more informations later).  All algorithms that produce
or use sba_explicit_* automata are changed to use tgba_digraph.
postproc has been rewritten using only tgba_digraph, and this required
changing the return types of many algorithms from tgba* to
tgba_digraph*.

* src/bin/dstar2tgba.cc, src/bin/ltlfilt.cc, src/dstarparse/dra2ba.cc,
src/dstarparse/dstar2tgba.cc, src/dstarparse/nra2nba.cc,
src/dstarparse/nsa2tgba.cc, src/dstarparse/public.hh,
src/tgba/tgbagraph.hh, src/tgba/tgbasafracomplement.cc,
src/tgbaalgos/compsusp.cc, src/tgbaalgos/compsusp.hh,
src/tgbaalgos/degen.cc, src/tgbaalgos/degen.hh,
src/tgbaalgos/dotty.cc, src/tgbaalgos/minimize.cc,
src/tgbaalgos/minimize.hh, src/tgbaalgos/postproc.cc,
src/tgbaalgos/postproc.hh, src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/sccinfo.cc, src/tgbaalgos/stripacc.cc,
src/tgbaalgos/stripacc.hh, src/tgbaalgos/translate.cc,
src/tgbaalgos/translate.hh, src/tgbatest/ltl2tgba.cc,
wrap/python/spot.i: Update.

* src/tgbaalgos/sccfilter.cc, src/tgbaalgos/sccfilter.hh: Rewrite all
composable filters in a way that allow arguments to be passed.
(scc_filter_susp): New function.
* src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh (scc_ap_support):
New method.
* src/tgbaalgos/compsusp.cc: Adjust to use tgba_digraph, and
call the new scc_filter_susp().

This can only cause failure when running under valgrind (i.e., in the
test suite), but is not a problem in practice as the test is certain
to fail the entry->c check whenever entry->b is uninitialized.

* src/bddop.c (bdd_implies): Here.

Those cannot work now that automata are not labeled by formulas
anymore.

* src/tgbaalgos/isweakscc.cc, src/tgbaalgos/isweakscc.hh
(is_syntactic_weak_scc, is_syntactic_terminal_scc): Remove.

* src/tgbaalgos/dtgbacomp.cc, src/tgbaalgos/dtgbacomp.hh: Rewrite.
Also prefer simple loops over reachiter.
* src/tgbatest/det.test: Adjust.

* src/tgbaalgos/complete.cc, src/tgbaalgos/complete.hh
(tgba_complete_here): New method for tgba_digraph.
(tgba_complete): Rewrite using dupexp and the above.

* src/misc/common.hh (SPOT_RETURN): New macro.
* src/tgba/tgbagraph.hh (out, states, transitions): Use it.

The conversion is not complete, because the conversion from SERE to DRA
used for the closure operator is still building a tgba_explicit_formula.

* src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_fm.hh: Return
a tgba_digraph.
* src/priv/acccompl.cc: Simplify.
* src/graph/ngraph.hh: Add a way to iterate over all names.
* src/tgba/tgbagraph.hh (compute_support_conditions): Return something
useful.  It's actually used by the constructor of testing automata.
* src/tgbatest/wdba.test: Adjust to the fact that state are not
labeled by formulas anymore.
* src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc: Do not try to enable
UTF8 on automata anymore.

* src/dstarparse/dra2ba.cc: Use tgba_digraph instead of
tgba_explicit_number.
* src/tgbatest/dstar.test: Adjust.

* src/dstarparse/nra2nba.cc: Produce tgba_digraph instead
of tgba_explicit_number.
* src/tgbaalgos/sccinfo.hh (is_useful_state): Make sure
it is reachable.

* src/priv/accmap.hh (acc_mapper_consecutive_int): New class.
* src/dstarparse/nsa2tgba.cc: Build a tgba_digraph, and simplify
using acc_mapper_consecutive_int.