Added script allowing the required fields icons to show error

### Story
* https://www.pivotaltracker.com/story/show/68443700

### Notes
* It only acts when there's a `field_with_errors` on the page. 
* I love jQuery!
* One thing I noticed: The last field (confirm password) never shows as having an error, which strikes me as strange, but I guess that's an artifact of devise?

### Screenshot
![iconvalidation](https://cloud.githubusercontent.com/assets/2136286/2961588/61de87d2-dac8-11e3-9799-1cb2b3d6818a.png)