pywatchman: fix for windows 7 and earlier not supporting GetOverlappedResultEx
pywatchman: fix for windows 7 and earlier not supporting GetOverlappedResultEx

kwlzn/watchman,facebook/watchman,nodakai/watchman,wez/watchman,nodakai/watchman,wez/watchman,facebook/watchman,kwlzn/watchman,kwlzn/watchman,kwlzn/watchman,facebook/watchman,facebook/watchman,wez/watchman,nodakai/watchman,kwlzn/watchman,kwlzn/watchman,wez/watchman,wez/watchman,kwlzn/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,wez/watchman,wez/watchman,wez/watchman,facebook/watchman,nodakai/watchman,wez/watchman,nodakai/watchman,nodakai/watchman