Extract upstream KWSys using the following shell commands.

$ git archive --prefix=upstream-kwsys/ c9336bcf | tar x
$ git shortlog --no-merges --abbrev=8 --format='%h %s' d3ba91e1..c9336bcf
Brad King (2):
      86a24794 SystemTools: Fix GetActualCaseForPath drive letter case handling
      c9336bcf SystemTools: Optimize GetActualCaseForPath memoization