Including the Randen RNG

[ruuda]

Randen is a new random number generator that is fast and secure. There is a Rust port of the reference implementation, that relies on AES intrinsics and u128. The port has been published as a separate crate by @bhickey. rand maintainers, would you be open to integrating this into the rand crate itself?

CC @jan-wassenberg who is the main author of Randen.

[TheIronBorn]

Duplicate of #462.

Nice to hear there’s a rust port though, might be especially useful for our coming SIMD support.

[dhardy]

Possibly eventually, but see our policy on new PRNGs.