Have the trivial fetcher do no stats updating by default.

src/main/java/com/samskivert/depot/impl/DepotMarshaller.java

@@ -1039,9 +1039,6 @@ public class DepotMarshaller<T extends PersistentRecord> implements QueryMarshal
                                              DatabaseLiaison dl) throws SQLException {
                     return new TableMetaData(conn.getMetaData(), tableName);
                 }
-                public void updateStats (Stats stats) {
-                    // nothing doing
-                }
             });
         }
 

src/main/java/com/samskivert/depot/impl/Fetcher.java

@@ -35,6 +35,11 @@ public abstract class Fetcher<T>
         public T getCachedResult (PersistenceContext ctx) {
             return null;
         }
+
+        @Override // from Fetcher
+        public void updateStats (Stats stats) {
+            // nothing doing
+        }
     }
 
     /**