job management:

moved job code from thread_pool to job, jobs have an "execute" method now
  added two new jobs: delete_child_sa & rekey_child_sa
kernel interface:
  listens now for ACQUIRE & EXPIRE
  supports hard and soft lifetimes
  fires jobs for delete and rekey child sa
ike sa manager:
  can checkout IKE SAs by requid of owned CHILD SAs
we have now the infrastructure to do the rekeying... :-)

src/charon/sa/child_sa.h

@@ -58,6 +58,17 @@ typedef struct child_sa_t child_sa_t;
  */
 struct child_sa_t {
 	
+	/**
+	 * @brief Get the unique reqid of the CHILD SA.
+	 * 
+	 * Every CHILD_SA has a unique reqid, which is also 
+	 * stored down in the kernel.
+	 *
+	 * @param this 		calling object
+	 * @return 			reqid of the CHILD SA
+	 */
+	u_int32_t (*get_reqid)(child_sa_t *this);
+	
 	/**
 	 * @brief Allocate SPIs for a given proposals.
 	 *