Log Message:
Import asignify-20150220 as security/asignify.

signify tool is heavily inspired by signify used in OpenBSD. However, the main
goal of this project is to define high level API for signing files, validating
signatures and encrypting using public keys cryptography. Asignify is
designed to be portable and self-contained with zero external dependencies.
It uses blake2b as the hash function and ed25519 implementation from tweetnacl.