Features
    * Add the LMS post-quantum-safe stateful-hash asymmetric signature scheme.
      Signature verification is production-ready, but generation is for testing
      purposes only. This currently only supports one parameter set
      (LMS_SHA256_M32_H10), meaning that each private key can be used to sign
      1024 messages. As such, it is not intended for use in TLS, but instead for
      verification of assets transmitted over an insecure channel, particularly
      firmware images.
    * Add the LM-OTS post-quantum-safe one-time signature scheme, which is
      required for LMS. This can be used independently, but each key can only be
      used to sign one message so is impractical for most circumstances.