FuckIs.js support

This adds support for [Matt Diamond](https://github.com/mattdiamond)'s excellent [FuckIt.js](https://github.com/mattdiamond/fuckitjs) library. Stacksort scripts will now always succeed, for some value of 'script', and some value of 'succeed'.

From the [README](https://github.com/mattdiamond/fuckitjs/blob/master/README.md): *"FuckItJS uses state-of-the-art technology to make sure your javascript code runs whether your compiler likes it or not."*