Add a screen for "invite to follow me"
The current approach of using a pop-up menu to list the user's circles, for inviting a friend-of-a-friend to follow, is not going to scale well when the user has a large number of circles. And in the real world, there will inevitably be some user who decides to create 40 different circles for all their friends.
So we need a new screen where the user can pick which circle they would like to invite the friend-of-a-friend to follow.