APNS 苹果官方文档链接 https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/ApplePushService.html#//apple_ref/doc/uid/TP40008194-CH100-SW9
参考链接：http://www.cnblogs.com/taintain1984/p/3727440.html