more flat includes

[SVN r40253]

include/boost/fusion/include/empty.hpp

@@ -0,0 +1,12 @@
+/*=============================================================================
+    Copyright (c) 2001-2007 Joel de Guzman
+
+    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_EMPTY)
+#define FUSION_INCLUDE_EMPTY
+
+#include <boost/fusion/sequence/intrinsic/empty.hpp>
+
+#endif