Ajout fichier manquant suite à erreur de compilation Mingw.

Utilities/BGL/boost/non_type.hpp

+// -------------------------------------
+//
+//           (C) Copyright Gennaro Prota 2003.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+//
+// ------------------------------------------------------
+
+#ifndef BOOST_NON_TYPE_HPP_GP_20030417
+#define BOOST_NON_TYPE_HPP_GP_20030417
+
+
+namespace boost {
+
+  // Just a simple "envelope" for non-type template parameters. Useful
+  // to work around some MSVC deficiencies.
+
+ template <typename T, T n>
+ struct non_type { };
+
+
+}
+
+
+#endif // include guard