add read lock for websocket recv

fix issue120 & 103: add mutex to prevent data race in websocket write…

… message and use named return values for WritePkg

fix issue116: limit the reconnect times or duration

upgrade go from 1.4 to 1.20; when session is closed, no need do OnMes…

…sage; fix bufix: add tlsHandshake timeout to prevent readtimeout cause dead loop

fix the wrong tls config

using go timer

rename v1.4.7-rc3 to 1.4.8

remove alexstocks/goext & alexstocks/log4go

Feature:

 using uber zap logger;
Fix:
  split large packet to n*16KB packet;
  default session nil

using uber zap logger