添加后台eventHub，根据event推送的信息，检查token

[lengyijun]

• 在fileshare branch上，www/blochchain/shoppeer.js中，
• 看一下原版的 www/blockchain/util.js，那里import EventHub

[lengyijun]

connectAndRegisterBlockEvent() {
    // Setup event hubs 
    try {
      this._eventHubs[0].connect({full_block: true});
      this._eventHubs[0].registerBlockEvent(
          (block) => {
             this.emit('block', unmarshalBlock(block));
          },
          (err) => {
             console.log(err);
          }
      );
    } catch (e) {
      console.log(`Failed to connect and register block event. Error ${e.message}`);
      throw e;
    }
  }

[lengyijun]

chaincode的修改去掉，学习旧版代码的写法，单节点，对于上传listrequest设置setevent