introduced refcounting on policy and connections

aren't stored in the IKE_SA anymore, they are queried on the fly
	are immutable now, allows it to share them
policy selection based on traffic selectors, leads to valid lookup results
	rekeying queries the policy based on its traffic selectors

src/charon/sa/authenticator.c

@@ -50,6 +50,11 @@ struct private_authenticator_t {
 	 */
 	ike_sa_t *ike_sa;
 	
+	/**
+	 * auth_method to create own signature/mac/whatever..
+	 */
+	auth_method_t auth_method;
+	
 	/**
 	 * PRF taken from the IKE_SA.
 	 */
@@ -294,10 +299,8 @@ static status_t compute_auth_data (private_authenticator_t *this,
 									chunk_t other_nonce,
 									id_payload_t *my_id_payload,
 									bool initiator)
-{
-	connection_t *connection = this->ike_sa->get_connection(this->ike_sa);
-	
-	switch(connection->get_auth_method(connection))
+{	
+	switch(this->auth_method)
 	{
 		case SHARED_KEY_MESSAGE_INTEGRITY_CODE:
 		{
@@ -405,7 +408,7 @@ static void destroy (private_authenticator_t *this)
 /*
  * Described in header.
  */
-authenticator_t *authenticator_create(ike_sa_t *ike_sa)
+authenticator_t *authenticator_create(ike_sa_t *ike_sa, auth_method_t auth_method)
 {
 	private_authenticator_t *this = malloc_thing(private_authenticator_t);
 
@@ -420,6 +423,7 @@ authenticator_t *authenticator_create(ike_sa_t *ike_sa)
 	
 	/* private data */
 	this->ike_sa = ike_sa;
+	this->auth_method = auth_method;
 	this->prf = this->ike_sa->get_prf(this->ike_sa);
 	this->logger = logger_manager->get_logger(logger_manager, IKE_SA);