[noise] screech: Noise library in Rust (pre-alpha)

[Trevor Perrin]

I'm working on a Noise library in Rust (very rough!, don't use for
anything real yet):

https://github.com/trevp/screech

It uses "rust-crypto" to support 25519, AESGCM, ChaChaPoly, SHA256,
SHA512, and BLAKE2b.

TODO:
 - C interface
 - Noise pipes
 - Cmdline tool for testing

I'd like to check interop with anyone who supports Revision 17,
there's some test vectors in tests/lib.rs.


Trevor