caiguo

[MBAlertView](https://github.com/mobitar/MBAlertView/tree/master/MBAlertView) implement the alertview just like @MaxHasADHD said.

The security boot option is a bit confusing. After 12.2, does security boot have to be turned on for installing OSX, or can you still turn it off as long...

Thank you, that makes sense now.