Support for invitations

[juhangsin]

Currently we don't have invitation functionality in the system.

It needs to have 2 things:

1. When the non-existing user wants to have an account within the system, group owner/user will be able to send an invitation for the user to sign up
2. Group to be able to inviting an existing user who's not part of any group to be part of a specific group,

[juhangsin]

Question for @evert

When the admin sends an invite email to a none existing user, would the URL contain a token or is it just a generic invite email with the /register link? Since what we have is anyone can register, I just want to make sure, but I understand that in the future or for a specific client, they would want this auth system to work as an invite-only.

[evert]

I think starting off with a /register link is a pretty good start, but you are right.. this 100% needs to be tokenized for closed registration systems. I feel getting the initial flow right will help you make good steps in that direction though

[juhangsin]

Current user being able to create a new non-user is completed.
Next step is a current user being able to send an email with the URI link for /register

[evert]

See #186 for an updated ticket