Logging system for WAI applications.

Sample code:

 {-# LANGUAGE OverloadedStrings #-}
 module Main where

 import Blaze.ByteString.Builder (fromByteString)
 import Control.Monad.IO.Class (liftIO)
 import Data.ByteString.Char8
 import Network.HTTP.Types (status200)
 import Network.Wai
 import Network.Wai.Handler.Warp
 import Network.Wai.Logger

 main :: IO ()
 main = do
     aplogger <- stdoutApacheLoggerInit FromSocket True
     run 3000 $ logapp aplogger

 logapp :: ApacheLogger -> Application
 logapp aplogger req = do
     let status = status200
         len = 4
     liftIO $ aplogger req status (Just len)
     return $ ResponseBuilder status
         [("Content-Type", "text/plain")
         ,("Content-Length", pack (show len))]
         $ fromByteString "PONG"