Validation changes

Replaces #741

- Fields are now highlighted in green when filled and there is no error, including select, checkboxes and radio buttons
- Select boxes have been given a mobile friendly fascia to facilitate this
- Green ticks now only appear if there is a status message

![new validation](https://cloud.githubusercontent.com/assets/246023/2549760/023bfde4-b67b-11e3-8825-881954d6e0ea.png)