restructure the complementation code

The previous code was sometime doing the work of remove_fin() in
addition to complementing the acceptance conditions.  This separate
the two operations clearly.  Also the specialized code for
complementing weak automata is now a specialized code for remove_fin()
on weak automata.

* src/twaalgos/dtgbacomp.hh, src/twaalgos/dtgbacomp.cc: Rename as ...
* src/twaalgos/complement.hh, src/twaalgos/complement.cc: ... these.
* src/twaalgos/Makefile.am: Adjust.
* src/twaalgos/complement.hh (dtgba_complement): Rename as ...
(dtwa_complement): ... this, and restrict the purpose to completion
and accetance complementation.  Further acceptance simplification
can be done with remove_fin() and to_generalized_buchi().
* src/twaalgos/remfin.cc (remove_fin): Specialize handling of weak
automata using the code that was originally in dtgba_complement().
Also mark the output as state-based when the input has to Inf.
* src/twaalgos/postproc.cc, src/twaalgos/postproc.hh: Make sure
scc_filter is always called after to_generalized_buchi().
* bench/stutter/stutter_invariance_randomgraph.cc,
src/bin/ltlcross.cc, src/tests/ikwiad.cc, src/twaalgos/minimize.cc,
src/twaalgos/powerset.cc, src/twaalgos/stutter.cc: Adjust usage.
* src/tests/dstar.test, src/tests/ltl2dstar4.test,
src/tests/remfin.test: Adjust expected outputs.
* wrap/python/spot_impl.i: Export dtwa_complement().

src/twaalgos/complement.hh

@@ -0,0 +1,41 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et Développement
+// de l'Epita.
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include "twa/twagraph.hh"
+
+namespace spot
+{
+  /// \brief Complement a deterministic TωA
+  ///
+  /// The automaton \a aut should be deterministic.  It will be
+  /// completed if it isn't already.  In these conditions,
+  /// complementing the automaton can be done by just complementing
+  /// the acceptance condition.
+  ///
+  /// In particular, this implies that an input that use
+  /// generalized Büchi will be output as generalized co-Büchi.
+  ///
+  /// Functions like to_generalized_buchi() or remove_fin() are
+  /// frequently called after dtwa_complement() to obtain an easier
+  /// acceptance condition (maybe at the cost of loosing determinism.)
+  SPOT_API twa_graph_ptr
+  dtwa_complement(const const_twa_graph_ptr& aut);
+}