* src/twaalgos/product.cc, src/twaalgos/product.hh: Implement
the variance.
* src/bin/autfilt.cc: Expose it.
* src/tests/prodor.test: New file.
* src/tests/Makefile.am: Add it.
* NEWS: Mention it.

Flatten the formula ltl::formula hiearchy into a single ltl::vnode that
has an enumerator to distinguish the types of node, and a common
interface to access children, update reference counts, etc.  The
ltl::formula class is now a thin wrapper around an ltl::vnode pointer to
keep track of reference counts automatically.  Visitor are not used
anymore; we now have map() and traversor() methods that are more
concise.

This basically fixes #43, but should be followed by some fine tuning
that should now be localized to the formula.hh and formula.cc files.

Some statistics about this patch.  I started working on it on Sep 9, had
a first compiling version two weeks later on Sep 22, and it then took 5
days to fixes the ~70 distincts bugs that were introduced during the
conversion.  About 13200 lines were modified, and one third of those
were removed.

* src/ltlast/formula.cc, src/ltlast/formula.hh: Complete rewrite,
including what was in separate nearby files.
* src/ltlast/allnodes.hh, src/ltlast/atomic_prop.cc,
src/ltlast/atomic_prop.hh, src/ltlast/binop.cc, src/ltlast/binop.hh,
src/ltlast/bunop.cc, src/ltlast/bunop.hh, src/ltlast/constant.cc,
src/ltlast/constant.hh, src/ltlast/multop.cc, src/ltlast/multop.hh,
src/ltlast/unop.cc, src/ltlast/unop.hh, src/ltlvisit/dump.cc,
src/ltlvisit/dump.hh, src/ltlast/predecl.hh: Delete these files.  Their
feature have been merged in formula.hh and formula.cc.
* src/ltlast/visitor.hh, src/ltlvisit/clone.cc, src/ltlvisit/clone.hh,
src/ltlvisit/dump.hh, src/ltlvisit/postfix.cc, src/ltlvisit/postfix.hh:
Delete these files, as we do not use visitors anymore.
* bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, doc/org/tut01.org,
doc/org/tut02.org, doc/org/tut10.org, doc/org/tut22.org,
iface/ltsmin/ltsmin.cc, iface/ltsmin/ltsmin.hh,
iface/ltsmin/modelcheck.cc, src/bin/autfilt.cc,
src/bin/common_aoutput.cc, src/bin/common_aoutput.hh,
src/bin/common_finput.cc, src/bin/common_finput.hh,
src/bin/common_output.cc, src/bin/common_output.hh,
src/bin/common_trans.cc, src/bin/common_trans.hh, src/bin/dstar2tgba.cc,
src/bin/genltl.cc, src/bin/ltl2tgba.cc, src/bin/ltl2tgta.cc,
src/bin/ltlcross.cc, src/bin/ltldo.cc, src/bin/ltlfilt.cc,
src/bin/ltlgrind.cc, src/bin/randaut.cc, src/bin/randltl.cc,
src/kripke/kripkeexplicit.cc, src/kripke/kripkeexplicit.hh,
src/kripkeparse/kripkeparse.yy, src/ltlast/Makefile.am,
src/ltlenv/declenv.cc, src/ltlenv/declenv.hh, src/ltlenv/defaultenv.cc,
src/ltlenv/defaultenv.hh, src/ltlenv/environment.hh,
src/ltlparse/ltlparse.yy, src/ltlparse/public.hh,
src/ltlvisit/Makefile.am, src/ltlvisit/apcollect.cc,
src/ltlvisit/apcollect.hh, src/ltlvisit/contain.cc,
src/ltlvisit/contain.hh, src/ltlvisit/dot.cc, src/ltlvisit/dot.hh,
src/ltlvisit/exclusive.cc, src/ltlvisit/exclusive.hh,
src/ltlvisit/length.cc, src/ltlvisit/length.hh, src/ltlvisit/mark.cc,
src/ltlvisit/mark.hh, src/ltlvisit/mutation.cc,
src/ltlvisit/mutation.hh, src/ltlvisit/nenoform.cc,
src/ltlvisit/nenoform.hh, src/ltlvisit/print.cc, src/ltlvisit/print.hh,
src/ltlvisit/randomltl.cc, src/ltlvisit/randomltl.hh,
src/ltlvisit/relabel.cc, src/ltlvisit/relabel.hh,
src/ltlvisit/remove_x.cc, src/ltlvisit/remove_x.hh,
src/ltlvisit/simpfg.cc, src/ltlvisit/simpfg.hh,
src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh, src/ltlvisit/snf.cc,
src/ltlvisit/snf.hh, src/ltlvisit/unabbrev.cc, src/ltlvisit/unabbrev.hh,
src/parseaut/parseaut.yy, src/ta/taexplicit.cc, src/ta/tgtaexplicit.cc,
src/taalgos/minimize.cc, src/taalgos/tgba2ta.cc, src/tests/bare.test,
src/tests/checkpsl.cc, src/tests/checkta.cc,
src/tests/complementation.cc, src/tests/consterm.cc,
src/tests/emptchk.cc, src/tests/equalsf.cc, src/tests/ikwiad.cc,
src/tests/isop.test, src/tests/kind.cc, src/tests/length.cc,
src/tests/ltldo.test, src/tests/ltlfilt.test, src/tests/ltlgrind.test,
src/tests/ltlprod.cc, src/tests/ltlrel.cc,
src/tests/parse_print_test.cc, src/tests/parseaut.test,
src/tests/parseerr.test, src/tests/randtgba.cc, src/tests/readltl.cc,
src/tests/reduc.cc, src/tests/syntimpl.cc, src/tests/taatgba.cc,
src/tests/tostring.cc, src/tests/twagraph.cc, src/tests/utf8.test,
src/twa/acc.cc, src/twa/bdddict.cc, src/twa/bdddict.hh,
src/twa/bddprint.cc, src/twa/formula2bdd.cc, src/twa/formula2bdd.hh,
src/twa/taatgba.cc, src/twa/taatgba.hh, src/twa/twa.cc, src/twa/twa.hh
src/twa/twagraph.cc, src/twa/twagraph.hh, src/twa/twasafracomplement.cc,
src/twaalgos/compsusp.cc, src/twaalgos/compsusp.hh,
src/twaalgos/dtgbasat.cc, src/twaalgos/hoa.cc, src/twaalgos/lbtt.cc,
src/twaalgos/ltl2taa.cc, src/twaalgos/ltl2taa.hh,
src/twaalgos/ltl2tgba_fm.cc, src/twaalgos/ltl2tgba_fm.hh,
src/twaalgos/minimize.cc, src/twaalgos/minimize.hh,
src/twaalgos/neverclaim.cc, src/twaalgos/postproc.cc,
src/twaalgos/postproc.hh, src/twaalgos/powerset.cc,
src/twaalgos/powerset.hh, src/twaalgos/randomgraph.cc,
src/twaalgos/remprop.cc, src/twaalgos/remprop.hh, src/twaalgos/stats.cc,
src/twaalgos/stats.hh, src/twaalgos/stutter.cc, src/twaalgos/stutter.hh,
src/twaalgos/translate.cc, src/twaalgos/translate.hh,
wrap/python/ajax/spotcgi.in, wrap/python/spot.py,
wrap/python/spot_impl.i, wrap/python/Makefile.am,
wrap/python/tests/automata-io.ipynb, wrap/python/tests/formulas.ipynb,
wrap/python/tests/ltl2tgba.py, wrap/python/tests/ltlparse.py,
wrap/python/tests/ltlsimple.py, wrap/python/tests/randltl.ipynb: Adjust
to use the new interface.
* src/sanity/style.test: Accept more C++11 patterns.
* NEWS: Mention the change.

* src/twa/bdddict.cc, src/twa/bdddict.hh,
src/twaalgos/ltl2tgba_fm.cc: here.

* doc/org/tut22.org, src/ltlvisit/apcollect.cc,
src/ltlvisit/apcollect.hh, src/parseaut/parseaut.yy,
src/tests/ikwiad.cc, src/tests/tgbagraph.test,
src/tests/twagraph.cc, src/twa/twa.cc,
src/twa/twa.hh, src/twaalgos/ltl2tgba_fm.cc,
src/twaalgos/randomgraph.cc, src/twaalgos/relabel.cc,
src/twaalgos/stutter.cc, src/twaalgos/stutter.hh: here.

* src/parseaut/parseaut.yy: Keep track of named states.
* src/tests/parseaut.test: Test it.

* src/parseaut/parseaut.yy: Do not call YYABORT on errors
in headers.
* src/tests/parseaut.test: Test this.

* .gitignore, bench/dtgbasat/.gitignore, debian/.gitignore,
doc/org/.gitignore, src/tests/.gitignore, wrap/python/.gitignore: More
files to ignore.
* doc/org/ltlfilt.org: Erase some temporary files.

* src/parseaut/parseaut.yy: Here.
* src/tests/parseaut.test: More tests.

* NEWS: Mention the changes.
* doc/org/autfilt.org, doc/org/dstar2tgba.org,
doc/org/ltlcross.org, doc/org/tools.org, doc/org/tut20.org,
src/bin/man/dstar2tgba.x, src/bin/man/ltlcross.x: Adjust
documentation.
* src/bin/common_trans.cc: Use %O instead of %D, but keep %D
hidden for backward compatibility.

* src/parseaut/parseaut.yy, src/parseaut/scanaut.ll: All multiple
dstar automata to be chained.
* src/bin/dstar2tgba.cc: Loop over multiple automata in a file.
* src/tests/dstar.test: Test that.

Note that the parser is still not able to reader multiple dstar
automata.

* src/dstarparse/: Delete.
* configure.ac, src/Makefile.am, README: Adjust.
* src/parseaut/parseaut.yy, src/parseaut/scanaut.ll: Merge in the
dstarparser rules.
* src/bin/common_trans.cc, src/bin/common_trans.hh,
src/bin/dstar2tgba.cc, src/bin/ltlcross.cc, src/bin/ltldo.cc,
src/tests/ikwiad.cc: Adjust usage.
* src/tests/parseaut.test: Adjust expected output.

* src/dstarparse/dstarparse.yy: Rename most of the
rules, and adjust the result_ fields to better
match those in src/parseaut/parseaut.yy.

* src/parseaut/parseaut.yy: Here.
* src/tests/parseaut.test: Adjust.

* src/parseaut/public.hh (parsed_aut): Add a type field.
* src/parseaut/parseaut.yy: Fill it.
* src/dstarparse/dstarparse.yy: Use this field instead of
the private enumeration.

* src/sanity/style.test: Allow { on the same line as "enum class".

* doc/tl/tl.bib (babiak.12.tacas): Typos in authors.
Reported by Jan Strejček.

This was suggested by one of the reviewers of our LPAR'15 paper.

* src/twaalgos/dtgbasat.cc, src/twaalgos/dtgbasat.hh: Implement
the colored option.
* src/tests/satmin2.test: Test it.
* doc/org/satmin.org, NEWS: Document it.

* debian/copyright: Here.
* THANKS: Add Michael, who reported the problem.

* NEWS, configure.ac, doc/org/setup.org: Update version.

* doc/org/index.org, doc/org/ioltl.org: Add links.

* src/tests/bitvect.cc: Fix it, it was failing an assert() on 32bit
architectures because the subset test was done in the wrong order.
Reported by Christopher Ziegler.
* NEWS: Mention it.

Fixes #96, reported by Vitus Lam & Christopher Ziegler.

* src/bin/ltlcross.cc: Catch std::bad_alloc, skip those
products and the related tests.  Display a count of
those skipped tests at the end.
* NEWS: Mention it.
* src/tests/ltlcross3.test: Adjust expected error
message.

Reported by Christopher Ziegler.

* src/tests/uniq.test: For LC_ALL=C before sort.

This implies learning alternative rules for G, and W as well, since
those would use R.

Fixes #103.  Suggested by Joachim Klein.

* src/ltlvisit/unabbrev.cc, src/ltlvisit/unabbrev.hh: Implement the
new rules.
* doc/tl/tl.tex: Document the rules.
* src/tests/unabbrevwm.test: Test them.
* src/bin/ltlfilt.cc, NEWS: Mention that --unabbreviate accepts R.

Fixes #8.

* src/bin/dstar2tgba.cc: Here.

* src/dstarparse/dstarparse.yy, src/dstarparse/dstarscan.ll
src/dstarparse/parsedecl.hh, src/dstarparse/public.hh:
Adjust to return the same return types as parse_aut.
* src/dstarparse/fmterror.cc: Delete, we can use
the one of parse_aut.
* src/dstarparse/Makefile.am: Adjust.
* src/tests/ikwiad.cc, src/bin/dstar2tgba.cc,
src/bin/ltldo.cc: Adjust usage.
* src/bin/ltlcross.cc: The the result of dstar_parse() as-is, now that
it is a TωA like those produced by parse_aut().  As a consequence,
get rid of all the code storing statistics about the input
automaton.
* src/tests/ltlcross3.test, src/tests/ltl2dstar.test: Adjust expected
CSV output.
* doc/org/ltlcross.org, src/bin/man/ltlcross.x: Adjust to not
mention that %D performs a tranformation to Büchi.

Since we just removed that conversion, those can go as well.  Yay!

* src/tests/kv.test, src/twa/twamask.cc,
src/twa/twamask.hh, src/twa/twaproxy.cc,
src/twa/twaproxy.hh, src/twaalgos/scc.cc,
src/twaalgos/scc.hh: Delete.
* src/twaalgos/Makefile.am, src/twa/Makefile.am,
src/tests/Makefile.am, src/tests/ikwiad.cc: adjust.

* src/dstarparse/dstarparse.yy: Use the twa_graph_ptr to store the
acceptance condition.
* src/dstarparse/dra2ba.cc, src/dstarparse/dstar2tgba.cc,
src/dstarparse/nra2nba.cc, src/dstarparse/nsa2tgba.cc: Delete
all these conversion routines.
* src/dstarparse/public.hh, src/dstarparse/Makefile.am: Adjust.
* src/bin/dstar2tgba.cc: Adjust to call to_generalized_buchi()
instead.
* src/bin/ltlcross.cc: Adjust to call remove_fin() instead.
* src/bin/ltldo.cc: Use the parsed automaton as-is.
* src/tests/degenid.test, src/tests/dstar.test, src/tests/ikwiad.cc:
Adjust test cases.