Merge pull request #5 from yuelong-qin/master

添加gcm功能
添加发件箱功能
Merge branch 'master' of https://github.com/qinge/mail
完善发件箱数据加载功能
实现发件箱本地删除
添加gcm 服务器端jar包
Merge remote-tracking branch 'upstream/master'