Escape HTML, and fix spaces.

I fixed the issue of rendering spaces by substituting for `&nbsp;`. In addition I've made HTML strings render correctly.

![screen shot 2014-10-25 at 10 44 07 am](https://cloud.githubusercontent.com/assets/51608/4780567/94d4782c-5c6e-11e4-82ea-d36c082c07bd.png)

Re: http://www.longstorm.org/weekly/cito/2/