Code cleanup.
* mandos (ForkingMixInWithPipe.handle_ipc): Take "self" argument.
(IPv6_TCPServer): Split off attributes "enabled", "clients",
"use_dbus", "gnutls_priority", and methods
"server_activate", "enable", and "handle" into
separate class "MandosServer".
(MandosServer): New.
(main): Use MandosServer instead of IPv6_TCPServer.