Added a popover to show counter information for an edge and added scaling options.

![screen shot 2013-12-04 at 11 55 56 am](https://f.cloud.github.com/assets/5580289/1676708/30706670-5d1e-11e3-80f4-38e56bf017bc.png)

- When the user hover over an edge, a popover will be displayed to show all the counter information.
- Added a setting button on the right side of the nav and allow the user to scale the edge based on 4 different options.