User roles

[cliftonc]

Complete the user role model (partially done), to allow creation of roles, allow users to be mapped to roles (more than one), dealing with changes.

[cliftonc]

Users can now belong to multiple roles, and this is managed via the profiles page. Still TODO is to add the ability to create and manage roles and then their permissions.

[cliftonc]

Closing - will create an additional feature in the roadmap for permission based security.