[boost] [config] A few headers moved from detail into config module

Hi, In case you missed it on the other thread, a few headers have been moved to the config module from detail: boost/version.hpp boost/limits.hpp boost/detail/workaround.hpp Hopefully that isn't a controversial move, but if any of these are a problem, it's just a case of reverting the appropriate changeset in Boost2Git. You can see them at: https://github.com/ryppl/Boost2Git/commits/master Daniel