Port rjenkins1 and crush_ln algorithms from Ceph libcrush.
<br/>Below is the sample code to use this crate.
```rust
let (n1, n2, n3) = (1u32, 2u32, 3u32);
let hash = sepia_hash::rjenkins1::hash32_3(n1, n2, n3);
println!("hash={}", hash);
let ln_res = sepia_hash::crush_ln::crush_ln(hash & 0xffff);
println!("ln_res={}", ln_res);
```

### Credits
The original algorithms are from libcrush project at <https://github.com/ceph/libcrush>.

### License
Following the original source, this project is licensed under the GNU Lesser General Public License v2.1 (LGPL-2.1).