rust-scrypt 1.2.0

Bindings into C for Tarsnap's `Scrypt` algorithm
Documentation
== (262144, 8, 1)
test tests::bench_encrypt_scrypt ... bench: 847,925,928 ns/iter

== (262144, 8, 1) scrypt in  rust-crypto
1,048,613,490 ns/iter (+/- 71,465,325)

== (262144, 8, 1) create Keyfile with scrypt
2,083,085,136 ns/iter (+/- 28,494,933)