1 Socket receive messages:
3 a) From self, accept any commands.
4 b) From a friend, accept some commands.
5 c) From unknown friend, accept less commands, or queue
8 Example: add new friend
10 1) Receive message from unknown friend.
11 2) Add to queue (inbox?) for friendship.
12 3) Self connects, ask for last messages in queue (inbox).
13 4) Self sends message adding friend.