simpler more generic processTranscript'

This allows using functions that generate CreateProcess and passing the
result to processTranscript', which is more flexible, and also simpler
than the old interface.

This commit was sponsored by Riku Voipio.

Build/EvilLinker.hs

@@ -127,7 +127,7 @@ getOutput c ps environ = do
 	putStrLn $ unwords [c, show ps]
 	systemenviron <- getEnvironment
 	let environ' = fromMaybe [] environ ++ systemenviron
-	out@(_, ok) <- processTranscript' (\p -> p { Utility.Process.env = Just environ' }) c ps Nothing
+	out@(_, ok) <- processTranscript' ((proc c ps) { Utility.Process.env = Just environ' }) Nothing
 	putStrLn $ unwords [c, "finished", show ok]
 	return out