Update CoffeeScript to 1.6.3

I downloaded the 1.6.3 release from here:
http://coffeescript.org/extras/coffee-script.js

The file has the same contents byte-for-byte as this file, which is nicely tagged:
https://raw.github.com/jashkenas/coffee-script/1.6.3/extras/coffee-script.js

Thank you for cdnjs!