Partially fix XSS injections (at least the case when you use a tag for an element's contents).

Although fixing XSS completely is [quite difficult](http://www.coverity.com/srl/a-guide-to-fixing-xss-for-devs.html), this simple fix should at least fix the super obvious and useful case when you are using your model's properties to fill the contents of HTML elements.

This does not fix any time you try to use a model's properties in attributes or in other trickier contexts.