applied new changes from NATT team

DPD only done when no IPsec and IKE traffic processed
	minor changes here and there

src/charon/network/interfaces.c

@@ -147,6 +147,7 @@ interfaces_t *interfaces_create(u_int16_t port)
 	if (initialize(this) != SUCCESS)
 	{
 		destroy(this);
+		return NULL;
 	}
 
 	return &this->public;

src/charon/network/socket.c

@@ -395,9 +395,9 @@ static status_t initialize(private_socket_t *this)
 		int type = UDP_ENCAP_ESPINUDP;
 		if (setsockopt(this->natt_fd, SOL_UDP, UDP_ENCAP, &type, sizeof(type)) < 0)
 		{
-			this->logger->log(this->logger, ERROR, 
+			this->logger->log(this->logger, ERROR,
 							  "unable to set UDP_ENCAP on natt send socket! NAT-T may fail! error: %s",
-							  strerror(errno)); 
+							  strerror(errno));
 		}
 	}