Comment Screen

- Added comment screen

![untitled](https://cloud.githubusercontent.com/assets/4236592/5476413/8ff6e82e-8619-11e4-81e2-0a1f674bf03d.png)

In fact there are two pages here. You are not limited to one controller per page. One page can be very complex and have many different responsibilities. In this case there are two different pages that are managed by the same controller, and the functionality is not even finished yet, there is still the edit/remove comments/discussions features, so it will get more complex. You don't want to have a single controller manage everything.