security/R-cran-sodium: New port: R bindings to libsodium

Bindings to libsodium: a modern, easy-to-use software library for
encryption, decryption, signatures, password hashing and more. Sodium
uses curve25519, a state-of-the-art Diffie-Hellman function by Daniel
Bernstein, which has become very popular after it was discovered that
the NSA had backdoored Dual EC DRBG.

WWW: https://cran.r-project.org/web/packages/sodium/