First pass at displaying what can be managed

* Split the sites table into two, one containing sites that can be
managed, another those that can't
* When a user is admin, include a link to configure the site (CDN, TNA
timestamp etc.)
* Move the permissions message beneath the "Sites you manage" header
* For all organisations a user cannot edit, the sites table stays the
same
Use user's organisation in prototype

* Only show sites you manage/other sites when user belongs to that
organisation
View site configuration from prototype

- Add new SitesController
- Create configure route within sites
- View site configuration