Create ability to moderate users

[adamamyl]

There are user cases where it might be appropriate to have a site open to (public) registration, but where the existing ckan.auth.* functionality doesn't quite meet the needs.

Rather than have an external form or process for managing the users (e.g., re-route /user/register to a third-party form), it might be nice to do this in ckan.

2014-12-03 18:14:09 < amln> it kinda makes me think 'states' of users
2014-12-03 18:14:47 < amln> (pending, active, suspended, deleted, purged)
2014-12-03 18:16:20 < amln> but i think we've had some discussion in ckan terms under password management / resets.