lints!

Specifically, this will prevent 2 code smells:

1. glob: `use foo::*` is by default denied. `use self::sub::*` is fine, as way to uplift sub modules. For uses of bad globs, they must be covered with a `#[glob = "explanation"]` attribute.
2. str_to_string: Micro benchmarks show it's 5x slower than `&str.into_string()`. So this lint denies such usage.