rename src/ as spot/ and use include <spot/...>

* NEWS: Mention the change.
* src/: Rename as ...
* spot/: ... this, adjust all headers to include <spot/...> instead of
"...", and adjust all Makefile.am to search headers from the top-level
directory.
* HACKING: Add conventions about #include.
* spot/sanity/style.test: Add a few more grep to catch cases
that do not follow these conventions.
* .gitignore, Makefile.am, README, bench/stutter/Makefile.am,
bench/stutter/stutter_invariance_formulas.cc,
bench/stutter/stutter_invariance_randomgraph.cc, configure.ac,
debian/rules, doc/Doxyfile.in, doc/Makefile.am,
doc/org/.dir-locals.el.in, doc/org/g++wrap.in, doc/org/init.el.in,
doc/org/tut01.org, doc/org/tut02.org, doc/org/tut03.org,
doc/org/tut10.org, doc/org/tut20.org, doc/org/tut21.org,
doc/org/tut22.org, doc/org/tut30.org, iface/ltsmin/Makefile.am,
iface/ltsmin/kripke.test, iface/ltsmin/ltsmin.cc,
iface/ltsmin/ltsmin.hh, iface/ltsmin/modelcheck.cc,
wrap/python/Makefile.am, wrap/python/ajax/spotcgi.in,
wrap/python/spot_impl.i, wrap/python/tests/ltl2tgba.py,
wrap/python/tests/randgen.py, wrap/python/tests/run.in: Adjust.

spot/twaalgos/word.hh

@@ -0,0 +1,54 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
+//
+// 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 <spot/twaalgos/emptiness.hh>
+
+namespace spot
+{
+  class bdd_dict;
+
+  /// \brief An infinite word stored as a lasso.
+  struct SPOT_API twa_word final
+  {
+    twa_word(const twa_run_ptr run);
+    ~twa_word()
+    {
+      dict_->unregister_all_my_variables(this);
+    }
+
+    void simplify();
+
+    typedef std::list<bdd> seq_t;
+    seq_t prefix;
+    seq_t cycle;
+
+    bdd_dict_ptr get_dict() const
+    {
+      return dict_;
+    }
+
+    SPOT_API
+    friend std::ostream& operator<<(std::ostream& os, const twa_word& w);
+  private:
+    bdd_dict_ptr dict_;
+  };
+
+}