Revert everything related to Damien's work in 2008 (he will commit a new version soon).

Here are the reverted patches:
8c0d1003b0,
25a3114287,
9afbaf6342,
dc0005f4e1,
543190f2bc.

src/ltlenv/declenv.hh

@@ -1,4 +1,4 @@
-// Copyright (C) 2008 Laboratoire d'Informatique de Paris 6 (LIP6),
+// Copyright (C) 2004  Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
 //
@@ -23,7 +23,10 @@
 # define SPOT_LTLENV_DECLENV_HH
 
 # include "environment.hh"
-# include "internal/declenv.hh"
+# include <string>
+# include <map>
+# include "ltlvisit/destroy.hh"
+# include "ltlast/atomic_prop.hh"
 
 namespace spot
 {
@@ -35,9 +38,29 @@ namespace spot
     ///
     /// This environment recognizes all atomic propositions
     /// that have been previously declared.  It will reject other.
-    typedef spot::internal::declarative_environment<ltl_t>
-    declarative_environment;
+    class declarative_environment : public environment
+    {
+    public:
+      declarative_environment();
+      ~declarative_environment();
 
+      /// Declare an atomic proposition.  Return false iff the
+      /// proposition was already declared.
+      bool declare(const std::string& prop_str);
+
+      virtual ltl::formula* require(const std::string& prop_str);
+
+      /// Get the name of the environment.
+      virtual const std::string& name();
+
+      typedef std::map<const std::string, ltl::atomic_prop*> prop_map;
+
+      /// Get the map of atomic proposition known to this environment.
+      const prop_map& get_prop_map() const;
+
+    private:
+      prop_map props_;
+    };
   }
 }