add a bit more pre exit cleanup

OpenSim/Framework/Servers/BaseOpenSimServer.cs

@@ -108,16 +108,16 @@ namespace OpenSim.Framework.Servers
 
         protected override void ShutdownSpecific()
         {
-
-
+            Watchdog.Enabled = false;
             base.ShutdownSpecific();
-
+            
             MainServer.Stop();
 
             Thread.Sleep(5000);
-
+            Util.StopThreadPool();
             WorkManager.Stop();
 
+            Thread.Sleep(1000);
             RemovePIDFile();
             m_log.Info("[SHUTDOWN]: Shutdown processing on main thread complete.  Exiting...");
 

OpenSim/Framework/Util.cs

@@ -2852,6 +2852,16 @@ namespace OpenSim.Framework
             return stpi;
         }
 
+        public static void StopThreadPool()
+        {
+            if (m_ThreadPool == null)
+                return;
+            SmartThreadPool pool = m_ThreadPool;
+            m_ThreadPool = null;
+
+            try { pool.Shutdown(); } catch {}          
+        }
+
         #endregion FireAndForget Threading Pattern
 
         /// <summary>