Some additional boost headers required for linux thread support.

Boost/boost/none.hpp

@@ -0,0 +1,28 @@
+// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
+//
+// 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)
+//
+// See http://www.boost.org/libs/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  fernando_cacciola@hotmail.com
+//
+#ifndef BOOST_NONE_17SEP2003_HPP
+#define BOOST_NONE_17SEP2003_HPP
+
+#include "boost/none_t.hpp"
+
+// NOTE: Borland users have to include this header outside any precompiled headers
+// (bcc<=5.64 cannot include instance data in a precompiled header)
+//  -- * To be verified, now that there's no unnamed namespace
+
+namespace boost {
+
+none_t const none = ((none_t)0) ;
+
+} // namespace boost
+
+#endif
+