echo server added.

server.go

 		//put into user session based pipeline
 		AllInMessage <- in
 	}
+
+	//uncomment the followin two lines to enable echo test
+	// state, _ := echoCommand(in.header.FromUserName, in)
+	// reply = state.response
 	fmt.Fprint(w, reply)
 }
 
-// func (session) ProcessInput(w, r) {
-// 	//are we in an existing procedure
-// 	inProc, state := isInProc(openID) //if inside a procedure, resume last saved state
-// 	if inProc {
-// 		state = serveProc(state, in) //transit to new state
-// 		reply = state.response       //xml response
-// 	} else {
-// 		state, processed := serveCommand(openID, in) //menu or txt command e.g. search
-// 		if !processed {                              // transfer to Customer Service (kf)
-// 			reply = buildKfForwardMsg(openID, "")
-// 			kfSendTxt(openID, "未识别的命令，已转接校友会理事会，稍后答复您")
-// 		} else {
-// 			reply = state.response
-// 		}
-// 	}
-// 	log.Println(reply) //instant reply, answering user's request
-// 	w.Header().Set("Content-Type", "text/xml; charset=utf-8")
-// 	fmt.Fprint(w, reply)
-
-// 	if !isEndingState(state) {
-// 		err := saveChatState(openID, state.Procedure, state)
-// 		if err != nil {
-// 			log.Println("Error Cannot Save chat sate")
-// 			log.Println(err)
-// 			log.Println(state)
-// 		}
-// 	} else { //state ending
-// 		cleanProcedure(openID, state.Procedure)
-// 	}
-// 	return
-// }
-
 func readWechatInput(r *http.Request) (result InWechatMsg, valid bool) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {