Add the capability to set a decryption password for updating with an
encrypted dmg file.
This enables the the ability to update using an encrypted disk image without having to prompt the user for a password. This is useful when access to the application binaries is only available via distribution or from a location in which authentication is required. This can help prevent an attacker from having unwanted access to application binaries for reverse engineering.
This assists with a defense in depth approach to security.
