Clean up how the recessive flag works

[Eh2406]

This ended up being a big PR, but each commit is small and focused. The goal of this was to get cargo sweep -i -r to work on my documents folder.

Some things that needed to be fixed for my projects:

• Some cargo project specify a different name for the target dir.
• Some even use a shared folder several levels up from where the Cargo.toml is.
• Some, maybe just Cargo itself, have full projects in the target dir for testing.
• There are a lot of files in .git folder that do not need to be searched.

with this cargo sweep -i -r on my documents is fast and reliable enough to add to my rustup update script.

[holmgr]

Looks really good to me! Great work 👍

[Eh2406]

Thanks for letting me work on your project!

[holmgr]

No problem, I do very much appreciate anyone who wants to contribute to this project! :)