New comment font & tweaks

New font and various minor tweaks to the comment design.

Old
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![image](https://f.cloud.github.com/assets/960919/2451201/fb9e6242-aec3-11e3-94c0-1b659a446a40.png)

New
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![image](https://f.cloud.github.com/assets/960919/2451202/04d38644-aec4-11e3-9c08-9cd447a51377.png)