attribute gateway_connections.
(oop_read_service): Fixed cut and paste errors in error messages.
(make_lsh_connection): Initialize gateway_connections.
(gateway_accept): New command.
(expr make_gateway_setup): Moved from gateway_commands.c.
(class lsh_options): New attributes, use_gateway, start_gateway,
stop_gateway, and gateway.
(make_options): Initialize gateway related attributes.
(main_options): Use an enum to define option values. New options
--use-gateway, --no-use-gateway, -G, --start-gateway,
--stop-gateway.
(main_argp_parser): Handle gateway related options.
(fork_lsh_transport): Return a plain fd, not an object.
(main): Start and stop gateway, as appropriate. Use a loop with
object_queue_is_empty and object_queue_remove_head, instead of the
FOR_OBJECT_QUEUE macro.

Rev: src/lsh.c:1.200.2.21