status --json now shows most things

Left out the backend usage graph for now, and bad/temp directory sizes
are only displayed when present. Also, disk usage is returned as a string
with units, which I can see changing later.

Messages.hs

@@ -68,17 +68,17 @@ showEndFail :: Annex ()
 showEndFail = showEndResult False
 
 showEndResult :: Bool -> Annex ()
-showEndResult b = handle (JSON.end b) $ putStrLn msg
+showEndResult ok = handle (JSON.end ok) $ putStrLn msg
 	where
 		msg
-			| b = "ok"
+			| ok = "ok"
 			| otherwise = "failed"
 
 showErr :: (Show a) => a -> Annex ()
 showErr e = warning' $ "git-annex: " ++ show e
 
 warning :: String -> Annex ()
-warning w = warning' (indent w)
+warning = warning' . indent
 
 warning' :: String -> Annex ()
 warning' w = do
@@ -88,7 +88,7 @@ warning' w = do
 		hPutStrLn stderr w
 
 indent :: String -> String
-indent s = join "\n" $ map (\l -> "  " ++ l) $ lines s
+indent = join "\n" . map (\l -> "  " ++ l) . lines
 
 {- Shows a JSON value only when in json mode. -}
 maybeShowJSON :: JSON a => [(String, a)] -> Annex ()
@@ -105,9 +105,8 @@ showCustom command a = do
 	handle (JSON.end r) q
 
 showHeader :: String -> Annex ()
-showHeader h = handle q $ do
-	putStr $ h ++ ": "
-	hFlush stdout
+showHeader h = handle q $
+	flushed $ putStr $ h ++ ": "
 
 showRaw :: String -> Annex ()
 showRaw s = handle q $ putStrLn s
@@ -126,12 +125,11 @@ setupConsole = do
 	hSetBinaryMode stderr True
 
 handle :: IO () -> IO () -> Annex ()
-handle json normal = do
-	output <- Annex.getState Annex.output
-	case output of
-		Annex.NormalOutput -> liftIO normal
-		Annex.QuietOutput -> q
-		Annex.JSONOutput -> liftIO json
+handle json normal = Annex.getState Annex.output >>= go
+	where
+		go Annex.NormalOutput = liftIO normal
+		go Annex.QuietOutput = q
+		go Annex.JSONOutput = liftIO json
 
 q :: Monad m => m ()
 q = return ()