Runner description editing improvements

Hi folks.

Here's a few improvements you may be interesting:
1) There was a bug when clicking "edit" on runner row: because of lack of preventDefault page was reloading
2) I added couple of styles to make "save" button look nicer
3) I added "cancel" button to cancel description editing

![screen shot 2014-03-21 at 10 14 47 pm](https://f.cloud.github.com/assets/39785/2486912/3630ab66-b12d-11e3-9275-ea064d932be8.png)