Container titles are sticky on mobile

Just had this idea, tell me what you think. Not sure what type of metrics to measure to see if it has any impact but I thought it was cool. Maybe it's not. Tell me if that's worth something and I'll show it to designers before anything goes in.

![sticky](https://f.cloud.github.com/assets/85783/1586873/19f3154a-522f-11e3-997d-a1fd3095e0a4.gif)