pull in Win32-extras, to be able to get current process id in Windows

Fixed up a number of things that had worked around there not being a way to
get that.

Most notably, transfer info files on windows now include the process id,
since no locking is currently done. This means the file format varies
between windows and unix.

Assistant/WebApp/Control.hs

@@ -18,11 +18,14 @@ import Utility.LogFile
 import Utility.NotificationBroadcaster
 
 import Control.Concurrent
-#ifndef mingw32_HOST_OS
-import System.Posix (getProcessID, signalProcess, sigTERM)
-#endif
 import qualified Data.Map as M
 import qualified Data.Text as T
+#ifndef mingw32_HOST_OS
+import System.Posix (getProcessID, signalProcess, sigTERM)
+#else
+import System.Win32.Process.Current (getCurrentProcessId)
+import System.Win32.Console (generateConsoleCtrlEvent, cTRL_C_EVENT)
+#endif
 
 getShutdownR :: Handler Html
 getShutdownR = page "Shutdown" Nothing $
@@ -46,14 +49,14 @@ getShutdownConfirmedR = do
 	liftAssistant $ do
 		modifyDaemonStatus_ $ \status -> status { globalRedirUrl = Just url }
 		liftIO . sendNotification . globalRedirNotifier =<< getDaemonStatus
-#ifndef mingw32_HOST_OS
 	{- Wait 2 seconds before shutting down, to give the web
 	 - page time to load in the browser. -}
 	void $ liftIO $ forkIO $ do
 		threadDelay 2000000
+#ifndef mingw32_HOST_OS
 		signalProcess sigTERM =<< getProcessID
 #else
-	void $ liftIO exitSuccess
+		generateConsoleCtrlEvent cTRL_C_EVENT =<< getCurrentProcessId
 #endif
 	redirect NotRunningR