Fixed a number of CLI commands.
Refactored the StoreService/Manager stuff for common serializer pool.
diff --git a/cli/src/main/java/org/onlab/onos/cli/NodesListCommand.java b/cli/src/main/java/org/onlab/onos/cli/NodesListCommand.java
index 1057d6e..1e921b4 100644
--- a/cli/src/main/java/org/onlab/onos/cli/NodesListCommand.java
+++ b/cli/src/main/java/org/onlab/onos/cli/NodesListCommand.java
@@ -29,8 +29,8 @@
     };
 
     @Override
-    protected Object doExecute() throws Exception {
-        ClusterService service = getService(ClusterService.class);
+    protected void execute() {
+        ClusterService service = get(ClusterService.class);
         List<ControllerNode> nodes = newArrayList(service.getNodes());
         Collections.sort(nodes, ID_COMPARATOR);
         ControllerNode self = service.getLocalNode();
@@ -39,7 +39,6 @@
                   service.getState(node.id()),
                   node.equals(self) ? "*" : "");
         }
-        return null;
     }
 
 }