Feature/scenario stops

This adds the ability to add/delete stops in scenarios

![Uploading 3.png . . .]()

![2](https://cloud.githubusercontent.com/assets/1977405/4955361/ba32bd24-6694-11e4-872c-86f08c873c29.png)

Since this is specific to scenario add stops view, maybe it should be moved to scenarios/route-stops/ directory?