* FireQueueEmpty now checks if a measurable amount of time has passed, and if not it sleeps for a small amount of time. This throttles OnQueueEmpty calls where there is no callback or the callback is doing very little work

* Changed HandleQueueEmpty()'s Monitor.TryEnter() calls to locks. We want to take our time in this function and do all the work necessary, since returning too fast will induce a sleep anyways

OpenSim/Region/ClientStack/LindenUDP/UnackedPacketCollection.cs

@@ -125,10 +125,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                             expiredPackets = new List<OutgoingPacket>();
                         expiredPackets.Add(packet);
                     }
-                    /*else
-                    {
-                        break;
-                    }*/
                 }
             }