Add a cleanup_acceptance() algorithm

* src/tgbaalgos/cleanacc.cc, src/tgbaalgos/cleanacc.hh: New file.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgba/acc.hh, src/tgba/tgba.hh (get_acceptance): Return a
reference.
* src/bin/autfilt.cc: Add a --cleanup-acceptance option.
* src/tgbatest/hoaparse.test: Test it.

src/tgbaalgos/cleanacc.hh

@@ -0,0 +1,32 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 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/>.
+
+#ifndef SPOT_TGBAALGOS_CLEANACC_HH
+# define SPOT_TGBAALGOS_CLEANACC_HH
+
+#include "tgba/tgbagraph.hh"
+
+namespace spot
+{
+  /// \brief Remove useless acceptance sets
+  SPOT_API void
+  cleanup_acceptance(tgba_digraph_ptr& aut);
+}
+
+#endif // SPOT_TGBAALGOS_CLEANACC_HH