Numerous automated fixes

[emchristiansen]

Each commit's message is the command that was run to generate that commit.

Note, neither cargo clippy --fix nor cargo +nightly fmt should change any semantics.

I did upgrade the packages using https://lib.rs/crates/cargo-edit, and everything still builds and all tests still pass.

BTW, you might want to add a commit-hook to automatically clippy --fix and fmt the code.

[RomarQ]

Thanks for the contribution 👍

Will have a look at the changes later today.

[RomarQ]

I moved the cargo upgrade commit to a different PR #38. Updating dependencies can be a nightmare sometimes, this needs some testing first.

[RomarQ]

The remaining changes look good to me 👍