OPT_OPT_NO_LOGIN_AUTH_MODE, OPT_LOGIN_AUTH_USER and
OPT_BANNER_FILE.
(lshd_options): New attributes with_loginauthmode,
loginauthmode_user and banner_file.
(make_lshd_options): Initialize new attributes.
(main_options): New options for login-auth-mode and banner-file.
(main_argp_parser): Make a userdb if using login-auth-mode too.
Bugfix; make sure self->userauth_algorithms is initialized, even
if we're using srp. Add a permissive userauth_none to
self->userauth_algorithms if using login-auth mode. Handle new
options.
(lshd_login_service): New class.
(make_lshd_login_service): New function.
(make_lshd_listen_callback): Read banner-file and pass as a string
to make_handshake_info is desired.
(main): Use the login service in login-auth mode.

Rev: src/lshd.c:1.159