Provides implementations of SnacCommands and associated command
factories for SNAC family 0x17, the family of commands used during
the login or "authorization" sequence.
This package encapsulates the entire authorization process; the sequence of
commands is generally:
-  Client sends KeyRequest
-  Server replies with KeyResponsewhich contains an
authorization key
-  Client sends AuthRequest, encrypting his or her password using
the key given in theKeyResponse(joscar does the encryption for
you)
-  Server sends AuthResponse, indicating either an error code or
a server, port, and login cookie for "basic online service"