make model change events opt-in per repository

NzbDrone.Core/Datastore/BasicRepository.cs

@@ -194,10 +194,17 @@ namespace NzbDrone.Core.Datastore
         }
 
 
-        protected virtual void PublishModelEvent(TModel model, RepositoryAction action)
+        private void PublishModelEvent(TModel model, RepositoryAction action)
+        {
+            if (PublishModelEvents)
             {
                 _messageAggregator.PublishEvent(new ModelEvent<TModel>(model, action));
             }
+        }
 
+        protected virtual bool PublishModelEvents
+        {
+            get { return false; }
+        }
     }
 }

NzbDrone.Core/Instrumentation/LogRepository.cs

@@ -23,10 +23,5 @@ namespace NzbDrone.Core.Instrumentation
             var oldIds = Query.Where(c => c.Time < DateTime.Now.AddDays(-30).Date).Select(c => c.Id);
             DeleteMany(oldIds);
         }
-
-        protected override void PublishModelEvent(Log model, Datastore.Events.RepositoryAction action)
-        {
-            //Don't publish log added events.
-        }
     }
 }