Discourage use of getServiceThreadPoolSize method.

Broadcasts should determine their own service thread pool size.

src/main/java/altk/comm/engine/CommEngine.java

@@ -521,6 +521,7 @@ public abstract class CommEngine extends HttpServlet
         broadcasts.put(broadcastId,  broadcast);
     }
 
+    @Deprecated
     public int getServiceThreadPoolSize()
     {
         return serviceThreadPoolSize;