Add more granular permission levels for users

[danigirl329]

There are only two permission levels for users: Admin / Designer The Admins are able to do everything and the Designers can mostly do everything but delete pages and access Admin screens.

I'd like to see more granular user levels in the CMS; the ability to delete pages but not be able to access other admin screens and possibly the ability to add page level permissions (IE ability to edit these 5 pages in the CMS and nothing more.)

[fitzgerald]

One note in testing today--admin users scored to a specific site can see the dropdown list of all sites. If they select one, they get redirected to login. We may want to not display that list of sites at all.