ospfd: Unify router and network LSA refresh logic with general refresher

* (general) Get rid of the router and network LSA specific refresh timers
  and make the general refresher do this instead. Get rid of the twiddling
  of timers for router/network LSA that was spread across the code.

  This lays the foundations for future, general LSA refresh improvements,
  such as making sequence rollover work, and having generic LSA delays.

* ospfd.h: (struct ospf) Bye bye to the router-lsa update timer thread
  pointer.
  (struct ospf_area) and to the router-lsa refresh timer.
* ospf_interface.h: Remove the network_lsa_self timer thread pointer
* ospf_lsa.h: (struct ospf_lsa) oi field should always be there, for benefit
  of type-2/network LSA processing.
  (ospf_{router,network}_lsa_{update_timer,timer_add}) no timers for these
  more
  (ospf_{router,network}_lsa_update) more generic functions to indicate that some
  router/network LSAs need updating
  (ospf_router_lsa_update_area) update router lsa in a particular area alone.
  (ospf_{summary,summary_asbr,network}_lsa_refresh) replaced by the general
  ospf_lsa_refresh function.
  (ospf_lsa_refresh) general LSA refresh function
diff --git a/ospfd/ospf_nsm.c b/ospfd/ospf_nsm.c
index 1ab6ce3..279d2a0 100644
--- a/ospfd/ospf_nsm.c
+++ b/ospfd/ospf_nsm.c
@@ -711,7 +711,7 @@
 		 LOOKUP(ospf_nsm_state_msg, old_state),
 		 LOOKUP(ospf_nsm_state_msg, state));
 
-      ospf_router_lsa_timer_add (oi->area);
+      ospf_router_lsa_update_area (oi->area);
 
       if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
 	{
@@ -719,7 +719,7 @@
 	    ospf_area_lookup_by_area_id (oi->ospf, oi->vl_data->vl_area_id);
 	  
 	  if (vl_area)
-	    ospf_router_lsa_timer_add (vl_area);
+	    ospf_router_lsa_update_area (vl_area);
 	}
 
       /* Originate network-LSA. */
@@ -730,10 +730,9 @@
 	      ospf_lsa_flush_area (oi->network_lsa_self, oi->area);
 	      ospf_lsa_unlock (&oi->network_lsa_self);
 	      oi->network_lsa_self = NULL;
-	      OSPF_TIMER_OFF (oi->t_network_lsa_self);
 	    }
 	  else
-	    ospf_network_lsa_timer_add (oi);
+	    ospf_network_lsa_update (oi);
 	}
     }