Email bringup

* Add an option to notify every message.
* Add new check frequency options.
* Add don't fetch deleted messages from IMAP folder.
* Fix NPE while checking incoming settings.

Email跟进

* 添加"通知每一条消息"的选项.
* 添加更多的邮件查收频率选项.
* 添加不要获取IMAP文件夹中的已删除消息.
* 修复用户取消错误对话框时的NPE.
[1/2] All You Need is Dark

There's nothing you can do that can't be done
Nothing you can sing that can't be sung
Nothing you can say but you can learn to play the game
It's easy

There's nothing you can make that can't be made
No one you can save that can't be saved
Nothing you can do but you can learn to be you in time
It's easy

All you need is dark
All you need is dark
All you need is dark, dark
Dark is all you need

[2/2] in platform_packages_apps_UnifiedEmail