Adds encryption to the U2F public keys. While the public keys cannot be used to authenticate, only to validate someone is authenticated, if a rogue operator changed these in the database they may be able to bypass 2FA. This prevents that.
Allow users to configure the TOTP Algorithm and Digits. This should be used with caution as many TOTP applications do not support it. Some will also fail to notify the user that there is an issue. i.e. if the algorithm in the QR code is sha512, they continue to generate one time passwords with sha1. In addition this drastically refactors TOTP in general to be more user friendly by not forcing them to register a new device if the administrator changes the period (or algorithm).
Fixes#1226.
