Markdown formatting in comments, performance enhancements and other small 'improvements'

Since I believe there's a bright future ahead for this addon, I went ahead and readied some more things for that future. I'll provide more comments in the code.

This PR depends on gkoberger/omnium#3

I didn't know directly where to put this, so I'll leave it up to you:
 * the markdown parser is https://github.com/chjj/marked - an awesome project and customizable (let's think about what kind of special syntax we can introduce!)
 * the highlighter is http://highlightjs.readthedocs.org/en/latest/ - well maintained and documented project. I downloaded the full version with all available highlighters from http://softwaremaniacs.org/soft/highlight/en/download/