MUMUP-1343: Search icon is confusing

Making the search bar/magnifying glass sleeker and more user-friendly.
![image](https://cloud.githubusercontent.com/assets/1919535/5273002/300f8efc-7a48-11e4-9e5e-2f4ef4cc7ed4.png)

Works on mobile too.
![image](https://cloud.githubusercontent.com/assets/1919535/5273023/7d9648b4-7a48-11e4-9224-da06dd54df92.png)