Merge branch 'android-ndk'

This branch comes with some preliminary changes for the user-land IPsec
implementation and the Android App.

One important change is that the UDP ports used by the socket-default plugin
were made configurable (either via ./configure or strongswan.conf).
Also, the plugin does randomly allocate a port if it is configured to 0,
which is useful for client implementations.  A consequence of these
changes is that the local UDP port used when creating ike_cfg_t objects has
to be fetched from the socket.

src/libcharon/sa/ikev1/tasks/informational.c

@@ -116,7 +116,8 @@ METHOD(task_t, process_r, status_t,
 							 notify_type_names, type, redirect);
 						/* Cisco boxes reject the first message from 4500 */
 						me = this->ike_sa->get_my_host(this->ike_sa);
-						me->set_port(me, IKEV2_UDP_PORT);
+						me->set_port(me, charon->socket->get_port(
+														charon->socket, FALSE));
 						this->ike_sa->set_other_host(this->ike_sa, redirect);
 						this->ike_sa->reauth(this->ike_sa);
 						enumerator->destroy(enumerator);