Merge pull request #6 from cmr/master

cargo-lite
replace mul_add in lerp with separate multiply and add

Many common CPUs (like the Intel Sandy Bridge in my laptop) don't support FMA
in hardware, so LLVM emulates it in software instead. Replacing the FMA with a
multiply and add sped up my benchmark by 3x on OS X and 30x inside a 32-bit
Linux VM.

This has the downside of losing some precision. If that isn't acceptable then
we could make this a compile-time option.
Merge pull request #7 from rlane/no-fma

replace mul_add in lerp with separate multiply and add
Refactor and re-implement

Refactors some of the code into modules. One major change is using gradient
coherent noise for perlin noise generation, which tends to have fewer
artifacts.
Merge pull request #8 from Aatch/master

Refactor and re-implement
Add Makefile and enable rust-ci doc export
Merge pull request #11 from bjz/make

Add Makefile and enable rust-ci doc export
fix coherency on the Z axis

The arguments to lerp were ordered incorrectly.
replace "extern mod" with "extern crate"
Merge pull request #12 from rlane/fix-z

fix coherency on the Z axis
Merge pull request #13 from cmr/master

cargo-lite!
Fix rand crate import
Fix some unnecessary_parens warnings
Merge pull request #14 from bjz/fix-build

Fix build
Update to latest Rust
Use chained API for initialising perlin source
Merge pull request #15 from bjz/source-api

Use chained API for initialising perlin source
Update to latest rust nightly
Merge pull request #16 from bjz/update

Update to latest rust nightly
Update for Cargo