Addition of Predef into Boost.. Note, the references are indirect (i.e. svn externals), as the real project is in github.

git-svn-id: http://svn.boost.org/svn/boost/trunk@85164 b8fc166d-592f-0410-95f2-cb63ce0dd405
* Big refactoring in order to reduce template and debug symbol bloat.
* Fixes #8698
* Implemented SCARY iterators

git-svn-id: http://svn.boost.org/svn/boost/trunk@85165 b8fc166d-592f-0410-95f2-cb63ce0dd405