reuse reqid when a ROUTED child_sa gets INSTALLED

fixed a bug in retransmission code
added support for the "keyingtries" ipsec.conf parameter
added support for the "dpddelay" ipsec.conf parameter
done some work for "dpdaction" behavior
some other cleanups and fixes

src/charon/config/configuration.h

@@ -36,34 +36,33 @@ typedef struct configuration_t configuration_t;
  * 
  * @ingroup config
  */
-struct configuration_t { 
+struct configuration_t {
 
 	/**
 	 * @brief Returns the retransmit timeout.
 	 *
-	 * A return value of zero means the request should not retransmitted again.
-	 * The timeout values are managed by the configuration, so 
-	 * another backoff algorithm may be implemented here.
+	 * A return value of zero means the request should not be retransmitted again.
+	 * The retransmission algorithm uses sequences of retransmits, in which
+	 * every sequence contains exponential delayed retransmits. These
+	 * sequences are compareable to the keyingtries mechanism used in pluto.
 	 *
 	 * @param this				calling object
-	 * @param retransmit_count	number of times a message was retransmitted so far
+	 * @param retransmitted		number of times a message was retransmitted so far
+	 * @param max_sequences		maximum number of retransmission sequences to allow
 	 * @return					time in milliseconds, when to schedule next retransmit
 	 */
-	u_int32_t (*get_retransmit_timeout) (configuration_t *this, u_int32_t retransmit_count);
+	u_int32_t (*get_retransmit_timeout) (configuration_t *this, 
+										 u_int32_t retransmitted, 
+										 u_int32_t max_sequences);
 	
 	/**
 	 * @brief Returns the timeout for an half open IKE_SA in ms.
-	 * 
-	 * Half open means that the IKE_SA is still in one of the following states:
-	 *  - INITIATOR_INIT
-	 *  - RESPONDER_INIT
-	 *  - IKE_SA_INIT_REQUESTED
-	 *  - IKE_SA_INIT_RESPONDED
-	 *  - IKE_AUTH_REQUESTED
-	 * 
+	 *
+	 * Half open means that the IKE_SA is still on a not established state
+	 *
 	 * @param this				calling object
 	 * @return					timeout in milliseconds (ms)
-	 */	
+	 */
 	u_int32_t (*get_half_open_ike_sa_timeout) (configuration_t *this);
 
 	/**
@@ -77,17 +76,6 @@ struct configuration_t {
 	 */	
 	u_int32_t (*get_keepalive_interval) (configuration_t *this);
 
-	/**
-	 * @brief Returns the DPD interval in ms.
-	 * 
-	 * The DPD interval defines the time after which a
-	 * DPD request packet should be sent.
-	 * 
-	 * @param this				calling object
-	 * @return					interval in seconds
-	 */	
-	u_int32_t (*get_dpd_interval) (configuration_t *this);
-
 	/**
 	 * @brief Destroys a configuration_t object.
 	 *