[boost] [1.38][updated libraries] Releaes Notes

Hello library developers, If you've made any changes to your library, and haven't added them to the release notes, you should do so now. You can either add them to the file at: https://svn.boost.org/svn/boost/website/public_html/beta/feed/history/boost_... Don't worry too much about syntax, I'll fix it if necessary. Or if that's too much trouble, email them to this list. It's exactly the same drill as the last few releases. If your library has a changelog in your library, and you just want me to pull the changes from that, let me know. thanks, Daniel