`go-flag`, a command-line parser for migrating from Go

I've published a new crate go-flag: https://crates.io/crates/go-flag

Unlike major command-line parsing libraries (such as structopt), the main focus of this library isn't functionality or ergonomics as a library. Instead, this is made to be behavior-compatible with Go's flag library to help people port their CLI tools from Go to Rust.