[boost] Proposed Boost.Detect library

It's been mentioned in the past that Boost.Config is not intended as a library for external use (e.g. it's for use inside of Boost). Thus, I was motivated to write the following awhile back: https://github.com/brycelelbach/detect Unlike Boost.Config, it also detects underlying system architecture. Enjoy. -- Bryce Lelbach aka wash boost-spirit.com px.cct.lsu.edu github.com/lll-project