Updated "namespace triplegit" to "namespace boost"

I changed "namespace triplegit" to "namespace boost" to meet boost guidelines
I also removed triplegit::boost, (lines 150-193 triplegit.hpp)

TODO:
1. add BOOST_ prefix to macros
2. change file names
3. change CATCH to BOOST_TEST with macros
4. migrate NiallsCPPUtilities to a details folder
5. refactor NiallsCPPUtilities as needed for inclusion into boost
Merge branch 'pre_boost_import' of https://github.com/BoostGSoC/boost.afio into pre_boost_import