Add OSX standalone app license bundle, and arrange for the About page

to link to it.

Assistant/WebApp/Documentation.hs

@@ -9,15 +9,36 @@
 
 module Assistant.WebApp.Documentation where
 
+import Assistant.Common
 import Assistant.WebApp
 import Assistant.WebApp.Types
 import Assistant.WebApp.SideBar
+import Assistant.Install (standaloneOSXAppBase)
 import Utility.Yesod
 
 import Yesod
 
+{- The full license info may be included in a file on disk that can
+ - be read in and displayed. -}
+licenseFile :: IO (Maybe FilePath)
+licenseFile = do
+	base <- standaloneOSXAppBase
+	return $ (</> "LICENSE") <$> base
+
 getAboutR :: Handler RepHtml
 getAboutR = bootstrap (Just About) $ do
 	sideBarDisplay
 	setTitle "About git-annex"
+	builtinlicense <- isJust <$> liftIO licenseFile
 	$(widgetFile "documentation/about")
+
+getLicenseR :: Handler RepHtml
+getLicenseR = do
+	v <- liftIO licenseFile
+	case v of
+		Nothing -> redirect AboutR
+		Just f -> bootstrap (Just About) $ do
+			sideBarDisplay
+			setTitle "License"
+			license <- liftIO $ readFile f
+			$(widgetFile "documentation/license")