message: Allow users to bypass doorman for testing
diff: @@ -253,6 +253,22 @@ behavior basp_broker::make_behavior() {
  system().registry().put(whom->id(), whom);
  instance.add_published_actor(port, whom, std::move(sigs));
  },
  + // received from test code to set up two instances without doorman
  + [=](publish_atom, scribe_ptr& ptr, uint16_t port,
  + const strong_actor_ptr& whom, std::set<std::string>& sigs) {
  + CAF_LOG_TRACE(CAF_ARG(ptr)
  + << CAF_ARG(port) << CAF_ARG(whom) << CAF_ARG(sigs));
  + CAF_ASSERT(ptr != nullptr);
  + auto hdl = ptr->hdl();
  + add_scribe(std::move(ptr));
  + if (whom)
  + system().registry().put(whom->id(), whom);
  + instance.add_published_actor(port, whom, std::move(sigs));
  + set_context(hdl);
  + instance.write_server_handshake(context(), get_buffer(hdl), port);
  + flush(hdl);
  + configure_read(hdl, receive_policy::exactly(basp::header_size));
  + },
  // received from middleman actor (delegated)
  [=](connect_atom, scribe_ptr& ptr, uint16_t port) {
  CAF_LOG_TRACE(CAF_ARG(ptr) << CAF_ARG(port));
  