Issue 17012 narrow page

This fixes [dartbug 17012](https://code.google.com/p/dart/issues/detail?id=17012). It isn't pretty, but its better than the wrapped code that exists on the page today. I also fixed the javascript padding found on that page, with the css change.

At size 13px, the most that can fit in the side-by-side code examples is 44 characters. At 11px or 12px, there is room for 51 characters.