Flow manager grouping

https://www.pivotaltracker.com/story/show/84324680
https://www.pivotaltracker.com/story/show/83174792

![screen shot 2014-12-15 at 4 29 42 pm](https://cloud.githubusercontent.com/assets/3692/5444328/9d0972a0-8477-11e4-89b0-26828455041c.png)