Connected board description to title bar on board index.

On the topic listing for a board, the description bar was floating away from the title_bar style used for the "Subject / Started by" etc bar. Here's an example of it connected. Looks nicer I think.

Before:
![messageindex-spacing-before](https://cloud.githubusercontent.com/assets/8311876/4037771/e83f12b0-2ca8-11e4-8d08-0c8c90d2acc4.png)
After:
![messageindex-spacing-after](https://cloud.githubusercontent.com/assets/8311876/4037775/eb288f10-2ca8-11e4-9271-5b8f171906e1.png)