[boost] [1.47.0] Merge request for quickbook+random

Hello, Please can I merge this change: https://svn.boost.org/trac/boost/changeset/72799/ There's a constexpr method in that file which isn't just a return statement, which was causing random (and libraries which depend on it) to fail on gcc 4.6.0 in C++0x mode. So the change just disables use of constexpr. A proper fix is pretty simple so I'll do that for the next release if necessary. Also this small documentation fix: https://svn.boost.org/trac/boost/changeset/72823/ thanks, Daniel