Adds new comment screen

Adds new comment screen when click pitch in on the discussion page;
- When 'hide' is clicked, this screen slides to the bottom;

![untitled](https://cloud.githubusercontent.com/assets/4236592/5459579/13299a8c-8554-11e4-9092-e7513505e3e4.png)

Like we discussed before, I don't believe this is the right approach. The authors are not needed in the discussion, they should be fetched from something like a `User` model. @naps62 I request your input on this, but if everyone agrees we can leave this pr like it is, but a card needs to be added for a refactor right away.