improve display of multiline messages in alerts

This better handles error messages formatted for console display, by
adding a <br> after each line.

Hmm, I wonder if it'd be worth pulling in a markdown formatter, and running
the messages through it?

Utility/INotify.hs

@@ -50,6 +50,9 @@ watchDir :: INotify -> FilePath -> (FilePath -> Bool) -> WatchHooks -> IO ()
 watchDir i dir ignored hooks
 	| ignored dir = noop
 	| otherwise = do
+		case errHook hooks of
+			Nothing -> noop
+			Just hook -> tooManyWatches hook dir
 		-- Use a lock to make sure events generated during initial
 		-- scan come before real inotify events.
 		lock <- newLock