refactor, start tcp pub/sub.

lichao

2021-06-23 c1e39e20ca42b21eeac8b5068fa1f921bf9a070f

 src/exported_symbols

@@ -5,6 +5,7 @@
   BHUnregister;
   BHRegisterTopics;
   BHQueryTopicAddress;
   BHQueryProcs;
   BHSubscribeTopics;
   BHStartWorker;
   BHHeartbeatEasy;