class type client_endpoint_connector =object..end
connect.method connect : connect_address ->
Unixqueue.event_system -> connect_status Uq_engines.engineconnect_address argument. If successful, the state of the engine
changes to `Done(status) where status contains the socket
details. The connection is established in the background.
The type of status will correspond to the type of connect address
(e.g. a `Socket address will return a `Socket status).
The close-on-exec flag of the created socket descriptor is always set.
The socket descriptor is always in non-blocking mode.