Add scrypt unit tests

Make sure our scrypt library is passing the test vectors provided at:
http://tools.ietf.org/html/draft-josefsson-scrypt-kdf-00#page-11

This will allow us to substitute in new Salsa20/8, PBKDF2, etc
implementations that are faster without breaking compatibility.

Change-Id: I89024b637e0075e5018526e4147148e6fc8e4d96
3 files changed