Escape illegal whitespace

A description of the issue can be found here: http://webcache.googleusercontent.com/search?q=cache:yOavSvo5LtQJ:timelessrepo.com/json-isnt-a-javascript-subset+&cd=1&hl=en&ct=clnk&gl=us

I'm not entirely sure how to actually write a meaningful spec for this?

(Unrelated, I had to update the include assertion syntax for the latest should.js to get the specs to pass)