[boost] [system] Patches to apply when BOOST_ERROR_CODE_HEADER_ONLY or BOOST_NO_EXCEPTIONS are defined

Hi, I have added some simple patches for these two tickets https://svn.boost.org/trac/boost/ticket/7347:duplicate symbol while BOOST_ERROR_CODE_HEADER_ONLY is defined https://svn.boost.org/trac/boost/ticket/7149:system failed to compile with BOOST_NO_EXCEPTIONS defined when -fno-exceptions is NOT used Could I apply them to trunk? Best, Vicente