Actually disconnect the socket rather than just unreffing it, since the IO

Actually disconnect the socket rather than just unreffing it, since the IO

	* libsoup/soup-connection.c (soup_connection_disconnect): Actually
	disconnect the socket rather than just unreffing it, since the IO
	code may be holding an extra ref on it.
	(send_request): connect to the "restarted" signal too
	(request_restarted): Deal with "Connection: close"

	* libsoup/soup-connection-ntlm.c (ntlm_authorize_pre): Make this
	not go into an infinite loop if the server only supports Basic.