* 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/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().

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.

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

* HACKING: Adjust requirements.  g++4.8 is now OK
for all our targets.
* iface/dve2/dve2.cc, src/dstarparse/dstarparse.yy
src/dstarparse/nsa2tgba.cc, src/graph/ngraph.hh,
src/ltlast/atomic_prop.cc, src/ltlast/binop.cc, src/ltlast/bunop.cc,
src/ltlast/multop.cc, src/ltlast/unop.cc, src/ltlvisit/mark.cc,
src/ltlvisit/relabel.cc, src/taalgos/emptinessta.cc,
src/taalgos/tgba2ta.cc, src/tgba/tgbaexplicit.hh, src/tgba/tgbagraph.hh,
src/tgba/tgbasafracomplement.cc, src/tgba/tgbatba.cc,
src/tgbaalgos/cycles.cc, src/tgbaalgos/degen.cc,
src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtgbasat.cc,
src/tgbaalgos/emptiness.cc, src/tgbaalgos/gtec/gtec.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/magic.cc,
src/tgbaalgos/ndfs_result.hxx, src/tgbaalgos/reachiter.cc,
src/tgbaalgos/scc.cc, src/tgbaalgos/sccfilter.cc, src/tgbaalgos/se05.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03.cc,
src/tgbaalgos/tau03opt.cc, src/tgbaalgos/weight.cc: Use emplace()
instead of insert(make_pair(...)) or insert(...::value_type(...)).

These were used in old experiments, but have not turned useful in
practice.  Not worth keeping and maintaining.

* src/tgbaalgos/cutscc.cc, src/tgbaalgos/cutscc.hh: Delete.
* bench/scc-stats/, bench/split-product/: Delete.
* configure.ac, src/tgbaalgos/Makefile.am, README, bench/Makefile.am:
Adjust.

* src/tgba/tgbagraph.hh (new_state, new_states, new_transitions, out,
trans_data): Delegate these useful graph methods so we do not have to
call get_graph().
* src/graphtest/tgbagraph.cc, src/tgbaalgos/dtbasat.cc,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dupexp.cc,
src/tgbaalgos/emptiness.cc, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/powerset.cc, src/tgbaalgos/randomgraph.cc,
src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/sccinfo.cc,src/tgbaalgos/simulation.cc: Simplify.

This translator algorithm is seldom used in practice because we work
with explicit automata everywhere, and this is only useful to build
symbolic automata.  Furthermore, the symbolic automata produced by this
algorithm are larger (when looked at explicitly) than those produced by
ltl2tgba_fm or other explicit translators.

The nice side effect of this removal is that we can also remove a lot of
supporting classes, that were relying a lot on BDDs.

* src/tgba/public.hh, src/tgba/statebdd.cc, src/tgba/statebdd.hh,
src/tgba/succiterconcrete.cc, src/tgba/succiterconcrete.hh,
src/tgba/tgbabddconcrete.cc, src/tgba/tgbabddconcrete.hh,
src/tgba/tgbabddconcretefactory.cc, src/tgba/tgbabddconcretefactory.hh,
src/tgba/tgbabddconcreteproduct.cc, src/tgba/tgbabddconcreteproduct.hh,
src/tgba/tgbabddcoredata.cc, src/tgba/tgbabddcoredata.hh,
src/tgba/tgbabddfactory.hh, src/tgbaalgos/ltl2tgba_lacim.cc,
src/tgbaalgos/ltl2tgba_lacim.hh, src/tgbatest/bddprod.test,
src/tgbatest/mixprod.cc, src/tgbatest/mixprod.test: Delete all these
files.
* bench/ltlcounter/Makefile.am, bench/ltlcounter/README,
bench/ltlcounter/plot.gnu, bench/ltlcounter/run, src/tgba/Makefile.am,
src/tgbaalgos/Makefile.am, src/tgbatest/Makefile.am,
src/tgbatest/cycles.test, src/tgbatest/dupexp.test,
src/tgbatest/emptchk.test, src/tgbatest/ltl2tgba.cc,
src/tgbatest/ltl2tgba.test, src/tgbatest/ltlcross.test,
src/tgbatest/ltlprod.cc, src/tgbatest/spotlbtt.test,
src/tgbatest/wdba.test, src/tgbatest/wdba2.test,
src/tgba/tgbaexplicit.hh, wrap/python/ajax/ltl2tgba.html,
wrap/python/ajax/spot.in, wrap/python/spot.i,
wrap/python/tests/interdep.py, wrap/python/tests/ltl2tgba.py,
wrap/python/tests/ltl2tgba.test: Adjust.

* src/tgbaalgos/powerset.cc, src/tgbaalgos/powerset.hh:
Use tgba_digraph.
* src/tgba/tgbagraph.hh: Improve interface.
* src/tgbaalgos/minimize.cc, src/tgbatest/powerset.cc: Adjust.

This was only used in ELTL stuff, which I just removed because it was
unused.

* src/ltlast/automatop.cc, src/ltlast/automatop.hh,
src/ltlast/formula_tree.cc, src/ltlast/formula_tree.hh,
src/ltlast/nfa.cc, src/ltlast/nfa.hh: Delete.
* src/ltlast/Makefile.am: Adjust.
* src/ltlast/allnodes.hh, src/ltlast/formula.hh, src/ltlast/predecl.hh,
src/ltlast/visitor.hh, src/ltltest/equals.cc, src/ltltest/ltlrel.cc,
src/ltltest/reduc.cc, src/ltlvisit/clone.cc, src/ltlvisit/clone.hh,
src/ltlvisit/dotty.cc, src/ltlvisit/lbt.cc, src/ltlvisit/mark.cc,
src/ltlvisit/postfix.cc, src/ltlvisit/postfix.hh,
src/ltlvisit/relabel.cc, src/ltlvisit/simplify.cc, src/ltlvisit/snf.cc,
src/ltlvisit/tostring.cc, src/tgba/formula2bdd.cc,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_lacim.cc, src/tgbatest/ltl2tgba.cc,
iface/dve2/dve2check.cc: Remove all references to automatop.

* src/eltlparse/.gitignore, src/eltlparse/Makefile.am,
src/eltlparse/eltlparse.yy, src/eltlparse/eltlscan.ll,
src/eltlparse/fmterror.cc, src/eltlparse/parsedecl.hh,
src/eltlparse/public.hh, src/eltltest/.gitignore,
src/eltltest/Makefile.am, src/eltltest/acc.cc, src/eltltest/acc.test,
src/eltltest/defs.in, src/eltltest/nfa.cc, src/eltltest/nfa.test,
src/tgbaalgos/eltl2tgba_lacim.cc, src/tgbaalgos/eltl2tgba_lacim.hh,
src/tgbatest/eltl2tgba.test: Delete these files.
* src/Makefile.am, src/tgbaalgos/Makefile.am, src/tgbatest/Makefile.am,
src/tgbatest/ltl2tgba.cc, src/tgbatest/ltlcross.test,
src/tgbatest/spotlbtt.test, README, configure.ac: Adjust.

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh,
src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/dtgbasat.hh: Use tgba_digraph
and modernize syntax slightly.

* src/tgbaalgos/emptiness.cc, src/tgbaalgos/emptiness.hh: Use
tgba_digraph instead of tgba_explicit_string.

* src/priv/accmap.hh (acc_mapper): Rename into...
(acc_mapper_string): ... this, and add
(acc_mapper_int): ... this variant.
* src/tgbaparse/tgbaparse.yy: Adjust to renaming.
* src/tgbaalgos/lbtt.cc: Use acc_mapper_int and build an explicit
automaton.
* src/tgbaalgos/lbtt.hh: Adjust return type.
* src/tgbatest/ltl2tgba.cc: Adjust to new return type.

* src/misc/common.hh (SPOT_UNIMPLEMENTED, SPOT_UNREACHABLE,
SPOT_UNREACHABLE_BUILTIN): New macros.
* src/bin/dstar2tgba.cc, src/bin/ltlcross.cc,
src/dstarparse/dstar2tgba.cc, src/eltlparse/eltlparse.yy,
src/ltlast/binop.cc, src/ltlast/bunop.cc, src/ltlast/constant.cc,
src/ltlast/formula_tree.cc, src/ltlast/multop.cc, src/ltlast/nfa.cc,
src/ltlast/unop.cc, src/ltlvisit/dotty.cc, src/ltlvisit/lbt.cc,
src/ltlvisit/lunabbrev.cc, src/ltlvisit/mark.cc,
src/ltlvisit/randomltl.cc, src/ltlvisit/simpfg.cc,
src/ltlvisit/simplify.cc, src/ltlvisit/snf.cc, src/ltlvisit/tostring.cc,
src/misc/intvcomp.cc, src/misc/minato.cc, src/tgba/bdddict.cc,
src/tgba/formula2bdd.cc, src/tgba/tgbasafracomplement.cc,
src/tgbaalgos/eltl2tgba_lacim.cc, src/tgbaalgos/ltl2taa.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_lacim.cc,
src/tgbaalgos/simulation.cc, src/tgbatest/ltl2tgba.cc:  Use them.
* src/sanity/style.test: Catch assert(0) and assert(!"text");

* src/graph/graph.hh (new_states): Call reserve().
* src/tgbaalgos/randomgraph.cc: Use tgba_digraph
instead of tgba_string_explicit.

* src/ltlenv/declenv.cc, src/ltlenv/declenv.hh,
src/ltlenv/defaultenv.cc, src/ltlenv/defaultenv.hh,
src/ltlenv/environment.hh, src/tgbaalgos/compsusp.cc: Declare name as
const.

* src/tgbaalgos/dtgbasat.cc, src/tgbaalgos/eltl2tgba_lacim.cc,
src/tgbaalgos/simulation.cc, src/tgbaalgos/tau03opt.cc: Fix
cases where bddtrue and bddfalse where used in a ternary operator.
* src/sanity/style.test: Allow bdd_true()/bdd_false() to be
used in ternary operators.

* src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh: Implement
the acc_filter_simplify filter, and generalize composition to
be n-ary.
* src/tgbaalgos/sccfilter.cc (used_acc): New method.

The new version currently supports removal of useless state as well as
removal of acceptance sets from non-accepting SCCs (the two versions).
It does not yet support simplifation of acceptance sets and removal of
suspendable formulae.  However the design, using filters that are
composed before being applied, should make it easier to implement.

* src/tgbaalgos/sccfilter.cc, src/tgbaalgos/sccfilter.hh: Implement
the new scc_filter and supporting classes.
* src/tgbaalgos/simulation.cc, src/tgbaalgos/simulation.hh: Use it.
The simulation now always return a tgba_digraph.
* src/tgbatest/sim.test: Adjust.

* src/tgbaalgos/simulation.cc: Buid a tgba_digraph as the result of the
simulation.
* src/tgba/tgbagraph.hh (create_namer): New function.
* src/tgbatest/basimul.test: Add an additional test case that caused a
bug fixed in a previous patch.
* src/tgbatest/sim.test: Adjust.

* src/tgbaalgos/sccfilter.cc,
src/tgbaalgos/sccfilter.hh (scc_filter_states): New overload taking
a tgba_digraph and some scc_info.

* src/graph/graph.hh (trans_iterator): Add operator->() and operator
bool().
* src/tgbaalgos/sccinfo.cc, src/tgbaalgos/sccinfo.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/ltl2tgba.cc: Use the new dump_scc_info_dot() function.

* src/tgbaalgos/dupexp.cc, src/tgbaalgos/dupexp.hh: Return the
association between new states and old states in a vector instead of a
map.
* src/tgbaalgos/simulation.cc: Adjust.

* src/graph/graph.hh (new_states): New.
* src/tgba/tgbagraph.hh (graph_t): Make it public.
* src/tgbaalgos/simulation.cc: Get read of the acc_compl_automaton
class and replace it by a loop over all states of a tgba_digraph.
Remove some useless data structures.

* src/tgbaalgos/dupexp.cc, src/tgbaalgos/dupexp.hh: Produce
a tgba_digraph instead of a tgba_explicit_number.
* src/tgbaalgos/simulation.cc: First pass to adjust to the use of
tgba_digraph as a return of tgba_dupexp_dfs() and tgba_dupexp_bfs().
Some maps have been replaced by vectors because states are indexed,
but more simplifications could be done.