Line audio scrubber with columns

## Before

![screen shot 2014-08-06 at 15 20 32](https://cloud.githubusercontent.com/assets/74132/3828107/d5c31098-1d74-11e4-834e-b86e6512a126.png)

## After

![screen shot 2014-08-06 at 15 27 38](https://cloud.githubusercontent.com/assets/74132/3828215/d526e23a-1d75-11e4-92a4-54fc4b2e1247.png)