app桌面图标的角标及推送通知栏消息的清除

通知栏的清除：
UILocalNotification *ln = [UILocalNotification new];
ln.applicationIconBadgeNumber = -1;
[[UIApplication sharedApplication] presentLocalNotificationNow:ln];

app角标的清除：
[UIApplication sharedApplication].applicationIconBadgeNumber -= 1;