convert to withCreateProcess for async exception safety

This handles all createProcessSuccess callers, and aside from process
pools, the complete conversion of all process running to async exception
safety should be complete now.

Also, was able to remove from Utility.Process the old API that I now
know was not a good idea. And proof it was bad: The code size went *down*,
despite there being a fair bit of boilerplate for some future API to
reduce.

Remote/Bup.hs

@@ -152,14 +152,26 @@ bupSplitParams r buprepo k src =
 
 store :: Remote -> BupRepo -> Storer
 store r buprepo = byteStorer $ \k b p -> do
-	let params = bupSplitParams r buprepo k []
 	showOutput -- make way for bup output
-	let cmd = proc "bup" (toCommand params)
 	quiet <- commandProgressDisabled
-	let feeder = \h -> meteredWrite p h b
-	liftIO $ if quiet
-		then feedWithQuietOutput createProcessSuccess cmd feeder
-		else withHandle StdinHandle createProcessSuccess cmd feeder
+	liftIO $ withNullHandle $ \nullh ->
+		let params = bupSplitParams r buprepo k []
+		    cmd = (proc "bup" (toCommand params))
+			{ std_in = CreatePipe }
+		    cmd' = if quiet
+			then cmd 
+				{ std_out = UseHandle nullh
+				, std_err = UseHandle nullh
+				}
+			else cmd
+		    feeder = \h -> meteredWrite p h b
+		in withCreateProcess cmd' (go feeder cmd')
+  where
+	go feeder p (Just hin) _ _ pid =
+		forceSuccessProcess p pid
+			`after`
+		feeder hin
+	go _ _ _ _ _ _ = error "internal"
 
 retrieve :: BupRepo -> Retriever
 retrieve buprepo = byteRetriever $ \k sink -> do