dupexp: rename to copy, and preserve named states on request

* src/twaalgos/dupexp.cc, src/twaalgos/dupexp.hh: Rename to...
* src/twaalgos/copy.cc, src/twaalgos/copy.hh: ... these.
Get rid of dupexp_bfs, rename dupexp_dfs as copy, and add
an option to preserve named states.
* src/twaalgos/Makefile.am, src/tests/dupexp.test,
src/tests/ikwiad.cc, src/tests/sccsimpl.test,
src/twa/twagraph.hh, src/twaalgos/dot.cc,
src/twaalgos/stutter.cc, wrap/python/spot_impl.i: Adjust.
* NEWS: Mention this change.

src/twaalgos/copy.hh

@@ -0,0 +1,39 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012, 2013, 2014, 2015 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
+// Copyright (C) 2003, 2004, 2005 Laboratoire d'Informatique de Paris
+// 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
+// Université Pierre et Marie Curie.
+//
+// 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 "misc/common.hh"
+#include "twa/fwd.hh"
+#include "twa/twa.hh"
+#include <vector>
+
+namespace spot
+{
+  /// \ingroup twa_misc
+  /// \brief Build an explicit automaton from all states of \a aut,
+  ///
+  /// This works for using the abstract interface for automata
+  SPOT_API twa_graph_ptr
+  copy(const const_twa_ptr& aut, twa::prop_set p,
+       bool preserve_names = false);
+}