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/child_sa.h

@@ -177,7 +177,7 @@ struct child_sa_t {
 	 * @return				SUCCESS or FAILED
 	 */
 	status_t (*update_hosts) (child_sa_t *this, host_t *new_me, host_t *new_other, 
-							  host_diff_t my_diff, host_diff_t other_diff);
+	host_diff_t my_diff, host_diff_t other_diff);
 	
 	/**
 	 * @brief Install the policies using some traffic selectors.
@@ -192,6 +192,22 @@ struct child_sa_t {
 	 */	
 	status_t (*add_policies) (child_sa_t *this, linked_list_t *my_ts_list, linked_list_t *other_ts_list);
 	
+	/**
+	 * @brief Get the traffic selectors of added policies of local host.
+	 *
+	 * @param this 		calling object
+	 * @return			list of traffic selectors
+	 */	
+	linked_list_t* (*get_my_traffic_selectors) (child_sa_t *this);
+	
+	/**
+	 * @brief Get the traffic selectors of added policies of remote host.
+	 *
+	 * @param this 		calling object
+	 * @return			list of traffic selectors
+	 */	
+	linked_list_t* (*get_other_traffic_selectors) (child_sa_t *this);
+	
 	/**
 	 * @brief Get the time of this child_sa_t's last use (i.e. last use of any of its policies)
 	 *