Using double borders for acceptance states in SBAs.

* src/tgbaalgos/dotty.hh (dotty_reachable): Take a new
assume_sba argument.
* src/tgbaalgos/dotty.cc (dotty_bfs): Take a new
mark_accepting_states arguments.
(dotty_bfs::process_state): Check if a state is accepting using
the state_is_accepting() method for tgba_sba_proxies, or by
looking at the first outgoing transition of the state.  Pass
the result to the dectorator.
(dotty_reachable): Adjust function.
* src/tgbaalgos/dottydec.hh, src/tgbaalgos/dottydec.cc,
src/tgbaalgos/rundotdec.hh, src/tgbaalgos/rundotdec.cc
(state_decl): Add an "accepting" argument, and use it to
decorate accepting states with a double border.
* src/tgbatest/ltl2tgba.cc: Keep track of whether the output
is an SBA or not, so that we can tell it to dotty().
* wrap/python/ajax/spot.in: Likewise.
* wrap/python/cgi-bin/ltl2tgba.in: Likewise.

src/tgbaalgos/dotty.hh

@@ -1,4 +1,4 @@
-// Copyright (C) 2003, 2004  Laboratoire d'Informatique de Paris 6 (LIP6),
+// Copyright (C) 2003, 2004, 2011  Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
 //
@@ -31,12 +31,17 @@ namespace spot
 
   /// \brief Print reachable states in dot format.
   /// \ingroup tgba_io
+  ///
+  /// If assume_sba is set, this assumes that the automaton
+  /// is an SBA and use double elipse to mark accepting states.
+  ///
   /// The \a dd argument allows to customize the output in various
   /// ways.  See \ref tgba_dotty "this page" for a list of available
   /// decorators.
   std::ostream&
   dotty_reachable(std::ostream& os,
 		  const tgba* g,
+		  bool assume_sba = false,
 		  dotty_decorator* dd = dotty_decorator::instance());
 }