Cleanup

[CosmicHorrorDev]

Just some more various cleanups. The commit messages are pretty self-descriptive.

[JayKickliter]

It's a minor nit, but since this is a cleanup PR, it could make sense cleanup uses like:

use std::cmp;
use std::collections::hash_map::DefaultHasher;
use std::error::Error as StdError;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::iter::repeat;
use std::marker::PhantomData;
use std::mem;

to

use std::{
    cmp,
    collections::hash_map::DefaultHasher,
    error::Error as StdError,
    fmt,
    hash::{Hash, Hasher},
    iter::repeat,
    marker::PhantomData,
    mem,
};