BUG: Fix kwsysSystem_Shell_GetArgumentForWindows to reset the windows trailing backslash count to zero when a make variable reference is encountered.

ENH: Set CMake Policy CMP0003 to NEW behavior to build without warnings with the upcoming CMake 2.6 release.

COMP: Avoid warning in kwsys IOStream.cxx when the helper functions are not needed.  Define one public symbol to avoid complaints from archivers about empty object files.

STYLE: Remove references to std:: inside KWSys, even in comments.  This will allow a commit check to be added.