Some small pedantic styling changes

pedantic emboldening and removing underlines from header links.

Turns this: 
![screen shot 2014-03-18 at 17 13 50](https://f.cloud.github.com/assets/1446145/2450948/b8bd09d6-aec0-11e3-866f-de17fae71669.png)

into this: 
![screen shot 2014-03-18 at 17 13 23](https://f.cloud.github.com/assets/1446145/2450955/bd20a514-aec0-11e3-86c9-ebd10b154420.png)