LU-2675 build: remove WinNT "support"

Remove the WinNT "support" code. It's not maintained or used.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I361bfce148a040db60d68d3c34a399415f2dd628
Reviewed-on: http://review.whamcloud.com/11385
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>