Port from 2.7 branch.

Shut down cleanly when Windows is shutting down.

lib/python/nt_svcutils/service.py

@@ -85,6 +85,11 @@ class Service(win32serviceutil.ServiceFramework):
         # Set the stop event - the main loop takes care of termination.
         win32event.SetEvent(self.hWaitStop)
 
+    # SvcStop only gets triggered when the user explictly stops (or restarts)
+    # the service.  To shut the service down cleanly when Windows is shutting
+    # down, we also need to hook SvcShutdown.
+    SvcShutdown = SvcStop
+
     def onStop(self):
         # A hook for subclasses to override
         pass