tools/update-authors.sh doesn't work on OSX #1120

If someone has the time to shave this yak it would be greatly appreciated.

The update-authors.sh script works fine on Linux but not on OSX where the file gets jumbled. I believe the problem is that the OSX version of awk doesn't maintain natural sorting like the Linux one does. This is frustrating for me since I split my time between my OSX and Linux computers but can only run this on Linux.

-1 to rewriting this in JavaScript btw, I'd like to see a scripting solution, preferably with minimal changes to the existing script, although I don't know if that's even possible.