Fix for opening a browser on a mac (or xdg-open on linux/bsd?)

Utility/WebApp.hs, didn't quite have the right definition to use 'open' instead of 'xdg-open' on OSX, the follow fixes that

diff --git a/Utility/WebApp.hs b/Utility/WebApp.hs
index 6936c66..0593dda 100644
--- a/Utility/WebApp.hs
+++ b/Utility/WebApp.hs
@@ -42,7 +42,7 @@ localhost = "localhost"
 runBrowser :: String -> IO Bool
 runBrowser url = boolSystem cmd [Param url]
        where
-#if MAC
+#if OSX
                cmd = "open"
 #else
                cmd = "xdg-open"

done, thanks

I guess I should really clone the repo and submit a stream of minor changes :P, @joeyh please let me know if you're getting annoyed with copy and pasting the small fixes from the bug/forums section.

If you're going to be writing some patches, a git repo I can pull from would make my life easier. --Joey