Add boilerplate reference to LICENSE_1_0.txt

include/boost/utility/detail/minstd_rand.hpp

@@ -5,6 +5,9 @@
 //
 // 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
+//
 // An implementation of minstd_rand that does not require
 // the Random library