[NEW] security/p5-Crypt-Ed25519

Hi, ports@:

Here is a patch to create new port security/p5-Crypt-Ed25519.
This module implements Ed25519 public key generation, message signing
and verification. It is a pretty bare-bones implementation that
implements the standard Ed25519 variant with SHA512 hash, as well as a
slower API compatible with the upcoming EdDSA RFC.

It build well and pass all tests on amd64-current system.

Cheers !
wen