Fixed left sidebar layout issue.

Before:
![image](https://cloud.githubusercontent.com/assets/3330262/5006992/83164c58-6a71-11e4-84f1-e72101e6479b.png)

After:
![image](https://cloud.githubusercontent.com/assets/3330262/5006970/4a0c06a0-6a71-11e4-9582-904ff98f773b.png)
![image](https://cloud.githubusercontent.com/assets/3330262/5006977/5dd9774e-6a71-11e4-8a98-e7f1e586539b.png)