r7633: this patch started as an attempt to make the dcerpc code use a given

event_context for the socket_connect() call, so that when things that
use dcerpc are running alongside anything else it doesn't block the
whole process during a connect.

Then of course I needed to change any code that created a dcerpc
connection (such as the auth code) to also take an event context, and
anything that called that and so on .... thus the size of the patch.

There were 3 places where I punted:

  - abartlet wanted me to add a gensec_set_event_context() call
    instead of adding it to the gensec init calls. Andrew, my
    apologies for not doing this. I didn't do it as adding a new
    parameter allowed me to catch all the callers with the
    compiler. Now that its done, we could go back and use
    gensec_set_event_context()

  - the ejs code calls auth initialisation, which means it should pass
    in the event context from the web server. I punted on that. Needs fixing.

  - I used a NULL event context in dcom_get_pipe(). This is equivalent
    to what we did already, but should be fixed to use a callers event
    context. Jelmer, can you think of a clean way to do that?

I also cleaned up a couple of things:

 - libnet_context_destroy() makes no sense. I removed it.

 - removed some unused vars in various places
(This used to be commit 3a3025485b)

source4/libcli/ldap/ldap_bind.c

@@ -144,7 +144,7 @@ NTSTATUS ldap_bind_sasl(struct ldap_connection *conn, struct cli_credentials *cr
 	DATA_BLOB input = data_blob(NULL, 0);
 	DATA_BLOB output = data_blob(NULL, 0);
 
-	status = gensec_client_start(conn, &conn->gensec);
+	status = gensec_client_start(conn, &conn->gensec, NULL);
 	if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
 		goto failed;