… types.

It was mainly added for testing, even though there are better ways
to test this without introducing redundancy for everyone.

…tly improved.

Previously it would have to lock `stdout` on each write, now this is done only once.

…ee::excludes()`.

Further, this change removes the `permission` module without replacement,
and moves `permissions` into `open`.

This corrects an artifact of this crate previously being name `gix-repository` and brings
these types semantically closer to where they are actually used.

…o better public API for `Cache`.

That way it's a bit clearer what it is doing and does away with
some rather dubious test code.

…nore` files from.

This allows better tuning and makes it more versatile for usage in any application, not
just `git`.

…mpty.