escape </script> in strings

If we don't keep the browser from misbehaving, this happens:
![Screen Shot 2013-03-21 at 5 51 46 PM](https://f.cloud.github.com/assets/507047/288907/d36d5f22-928a-11e2-8b9d-cc332e6ec37c.png)
...and we can't have that happen.

More on this issue here: http://stackoverflow.com/questions/8749001/escaping-html-entities-in-javascript-string-literals-within-the-script-block