DC2B-100:  improvement to the user management function of the administration interface of the AODN portal.

1) Delete of users is a soft delete now. When a user is deleted (inactive) the linkage between the users and datasets  remain but the user is not able to log into the system	and has no any permission.
2) Administrator users are able to delete other administrator users, except where that use is the last admin user in the system.
3) AAF token is read only in the edit user page for all users.
4) The create user button is hidden from all users.