V1.0.0

Implemented from scratch with no external dependencies:

  - X25519 (Curve25519) key exchange
  - ChaCha20-Poly1305 AEAD encryption (RFC 8439)
  - HKDF-SHA256 key derivation
  - scrypt passphrase KDF (N=2^14, r=8, p=1)
  - HMAC-SHA256 header MAC
  - Bech32 key encoding/decoding
  - Base64 (no-padding) body encoding
  - SHA-256 and Poly1305 primitives

Supported modes:
  - Public key encryption/decryption via X25519 (-e -r / -d -i)
  - Passphrase encryption/decryption via scrypt (-e -p / -d -p)
  - Key pair generation (-k)
  - Stdin/stdout and file I/O

Compatibility:
  - Compiles cleanly with gcc 2.95.4 (2001)
  - Tested on Debian 3 (woody, 2002) — worked perfectly
  - Files produced are byte-compatible with the official age tool
  - Requires only a POSIX system with /dev/urandom