Administrators UI

[michaelbromley]

Create a basic administrator module for the admin ui, including:

• CRUD on Administrators
• CRUD on Roles
• Assigning Administrators to Roles

Note - this module should not deal with Customers, even though Customers and Administrators are both a type of User. This is because, to the end-user, they are very different kinds of entities. Plus, only the SuperAdmin would typically be dealing with the Administrator CRUD operations, whereas viewing and editing Customer data would be routine for any kind of administrator.