KWSys 2015-12-03 (6bfc1aef)

Extract upstream KWSys using the following shell commands.

$ git archive --prefix=upstream-kwsys/ 6bfc1aef | tar x
$ git shortlog --no-merges --abbrev=8 --format='%h %s' 9596e98d..6bfc1aef
Rolf Eike Beer (6):
      9e9c8ae3 SystemTools: extend test coverage of SystemTools::MakeDirectory()
      3f3d9eb5 SystemTools: add basic tests for SystemTools::FindFile()
      9ca5f108 SystemTools: entirely remove the extension code on non-Windows platforms
      29f82f78 SystemTools: avoid needless copy of std::string
      ac667cdc SystemTools: remove 2 more explicit calls to FileIsDirectory()
      6bfc1aef SystemTools: do not call FileExists() before calling FileIsDirectory()