Boost "vendor" repo for K1JT projects

This repository contains a subset of the Boost project with libraries needed by K1JT project s such as WSJT-X. It contains two branches, upstream and master. To upgrade the content do the following:

git checkout upstream
rm -r *
# use the bcp tool to populate with the new Boost libraries
git commit -a -m "Updated Boost v1.63 libraries including ..."
git tag boost_1_63
git push origin
git checkout master
git merge upstream
git push origin

The resulting master branch is now ready to be git-subtree merged into any projects that need these libraries.