Check that interdependent invokers are empty when shutting down the PresentsInvoker in addition to

checking the PresentsInvoker itself and the DObjectMgr.  Expose waiting for all theses queues to
empty on PresentsInvoker such that Presents servers can do things like wait for all the queues to
empty before opening to the public.



git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5898 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/server/PresentsServer.java

@@ -150,6 +150,7 @@ public class PresentsServer
         // start the main and auth invoker threads
         _invoker.start();
         _authInvoker.start();
+        ((PresentsInvoker)_invoker).addInterdependentInvoker(_authInvoker);
 
         // provide our client manager with the injector it needs
         _clmgr.setInjector(injector);