IM架构资料收集

• http://www.cnblogs.com/allexw/archive/2012/12/25/2832618.html
• http://mobile.51cto.com/hot-439693.htm
• http://blog.youkuaiyun.com/educast/article/details/12869001
• http://my.oschina.net/pzh0819/blog/113946