Update dependencies and fix clippy lints

[barafael]

What it does:

Hopefully nothing! Just improved mostly the string handling, removed some unneeded clones etc.

Why it does it:

Cuz... low hanging fruit for code quality? You be the judge.

[ryanavella]

I wouldn't just call this "low hanging fruit." Some of these fix actual warnings, and currently the crate does not compile due to #![deny(warnings)]