Fix computation of support_conditions for bdd-based TGBA.

This fixes a bug in the powerset of such TGBA on the minimize branch.

* src/tgba/tgbabddconcrete.cc (compute_support_conditions): Also
account for the conditions from the acceptance relations.
* rc/tgba/tgbabddconcretefactory.hh, rc/tgba/tgbabddconcretefactory.cc
(acceptance_conditions_support): New variable to hold the value
of bdd_support(acceptance_conditions_support).
* src/tgba/tgbabddconcretefactory.cc (finish): Update
data_.acceptance_conditions_support.

src/tgba/tgbabddcoredata.hh

@@ -1,3 +1,5 @@
+// Copyright (C) 2009, 2011 Laboratoire de Recherche et Développement de
+// l'Epita (LRDE).
 // Copyright (C) 2003, 2005  Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
@@ -74,6 +76,9 @@ namespace spot
     /// \li "Acc" variables.
     bdd acceptance_conditions;
 
+    /// The value of \c bdd_support(acceptance_conditions)
+    bdd acceptance_conditions_support;
+
     /// \brief The set of all acceptance conditions used by the Automaton.
     ///
     /// The goal of the emptiness check is to ensure that