Switch to using govuk_admin_template

* Upgrade from Bootstrap 2 to Bootstrap 3
* Upgrade jQuery, jQuery UI, formtastic, formtastic-bootstrap
 * Switch from using deprecated `commit_button`
* Update javascript to work with latest jQuery
  * `live` is deprecated
* Update markup to conform with newest bootstrap patterns
  * Accordion pattern when editing an edition becomes a set of rearrangeable panels
* Add breadcrumbs for easier navigation
* Remove CSS for sorted tables, history diff view and others — features aren't in this app