Reportback initial markup

Initial code for new reportback interface.

Styles will be broken out into smaller modules where applicable and added to Neue. Hard-coded markup will be converted to Drupal theming functions and templates. This is just the initial pass to establish the styles and required markup.

@DFurnes @sbsmith86 

CC: @barryclark @aaronschachter 

For visual reference, desktop view:
![reportback layout](https://cloud.githubusercontent.com/assets/105849/5381531/312e9f20-8070-11e4-8739-0661f573e1b9.png)

PS: all this new markup code is still behind the feature flag.