Default font size for <pre>

Default font size for <pre> makes request and response log in mock service web ui much more readable than 8px and is much closer in size to the rest of the page text

8px: 
![pre8px](https://f.cloud.github.com/assets/349523/1654217/b6f9a5aa-5b46-11e3-976f-5c3e7d35f75e.png)

Default:
![predefaultsize](https://f.cloud.github.com/assets/349523/1654219/bd2ce8d8-5b46-11e3-9587-e68a02a9dfa4.png)