Extract upstream KWSys using the following shell commands.

$ git archive --prefix=upstream-kwsys/ beef6819 | tar x
$ git shortlog --no-merges --abbrev=8 --format='%h %s' f6c4c247..beef6819
Brad King (1):
      beef6819 SystemTools: Implement IsSubDirectory without loop

Change-Id: Ifab0c0384c7fbf1f9fc934918573a49b38f7bc0a