pgf-http now uses $datadir/www instead of ./www as the document root

Along with the changes to Setup.hs it should now be enough to do

	cabal install
	pgf-http
	open http://localhost:41296/

to run the PGF service locally and play with some example grammars in minibar.

src/server/pgf-http.hs

@@ -2,23 +2,34 @@
 import Network.CGI(requestMethod,getVarWithDefault,logCGI,handleErrors,liftIO)
 import System.Environment(getArgs)
 import System.Directory(getDirectoryContents)
-import System.FilePath(takeExtension,takeFileName,takeDirectory)
+import System.FilePath(takeExtension,takeFileName,takeDirectory,(</>))
        
-import RunHTTP(runHTTP)
+import RunHTTP(runHTTP,Options(..))
 import ServeStaticFile(serveStaticFile)
 import PGFService(cgiMain',getPath,stderrToFile,logFile,newPGFCache)
 import FastCGIUtils(outputJSONP,handleCGIErrors)
 
+import Paths_gf_server(getDataDir)
+
 main :: IO ()
-main = do stderrToFile logFile
+main = do datadir <- getDataDir
+          let defaults = Options { documentRoot = datadir</>"www",
+                                   port = 41296 }
           cache <- newPGFCache
           args <- getArgs
-          port <- case args of
-                    []     -> return 41296
-                    [port] -> readIO port
-          httpMain cache port
+          options <- case args of
+                       []     -> return defaults
+                       [port] -> do p <- readIO port
+                                    return defaults{port=p}    
+          putStrLn $ "Starting HTTP server, open http://localhost:"
+                     ++show (port options)++"/ in your web browser.\n"
+          print options
+          putStrLn $ "logFile="++logFile
+          stderrToFile logFile
+          httpMain cache options
 
-httpMain cache port = runHTTP port (do log ; serve =<< getPath)
+
+httpMain cache options = runHTTP options (do log ; serve =<< getPath)
   where
     log = do method <- requestMethod
              uri    <- getVarWithDefault "REQUEST_URI" "-"