change the adding of users to groups to an "invitation"

[Robert Jäschke]

Currently, every group admin can add users to its group without the user noticing it or having the chance to deny it.

Please implement an invitation process similar to the user registration process where the user gets an invitation e-mail and is put into a pending group user table. When the user accepts the group invitation, he or she is added to the group.

[Robert Jäschke]

BTW: Clemens has implemented the "pending user" registration process - so he's a good contact person for questions. :-)

[Daniel Zoller]

should be resolved @thoni !?

[Thomas Niebler]

Is resolved.