用户注册使用有代码向用户邮箱中发送链接，然后用户点击链接激活账号
邮箱激活用户
http://www.cxyclub.cn/n/60763/
http://download.csdn.net/detail/martin_yl/8331813
http://zfy421.iteye.com/blog/1691874
找回密码
http://zfy421.iteye.com/blog/1691874
http://blog.sina.com.cn/s/blog_704b85230100nf8k.html
http://download.csdn.net/detail/a147017547/3737549
http://blog.csdn.net/tjcyjd/article/details/6886351