Provide a way to disable for admin users

Problem/Motivation

It is not currently possible to disable the system for admin users, people who have a role that is configured as an admin role (one with the "is_admin" flag set to TRUE).

Proposed resolution

Provide a solution to disable the functionality outside of the permission.

Remaining tasks

Work out a solution to this.

User interface changes

TBD

API changes

TBD

Data model changes

TBD