Perlin noise in Rust

This is a fast implementation of Perlin noise in Rust.

It has no dependencies, is #![no_std] and #[forbid(unsafe_code)].

lib.rs:

Perlin noise in 2D and 3D. Translated from the reference Java implementation at https://mrl.cs.nyu.edu/~perlin/noise/ and https://mrl.cs.nyu.edu/~perlin/paper445.pdf