mbed TLS 2.3.0, Virgil Security 2.0.0

Features

• Implement Ed25519 and X25519 key parse and key write draft-ietf-curdle-pkix-01
• Implement EdDSA draft-irtf-cfrg-eddsa-08
• Implement X25519 RFC7748
• Add AMD64 optimizations for Ed25519 library

Changes

• Make ECIES algorithm agnostic to a PK keypair