add automatic hash function creation

include/boost/fusion/include/hash.hpp

@@ -0,0 +1,12 @@
+/*=============================================================================
+    Copyright (c) 2014 Christoph Weiss
+
+    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)
+==============================================================================*/
+#if !defined(FUSION_INCLUDE_HASH)
+#define FUSION_INCLUDE_HASH
+
+#include <boost/fusion/sequence/hash.hpp>
+
+#endif