[boost] [Container][Move] #if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE): boost::move_backward is undefined

Hey, If BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE is defined, then compiling Boost.Container fails because its missing boost::move_backward. Patch is attached. Ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu