Make CODEOWNERS more flexible

[caniszczyk]

At the moment, you can require a review for everything list in CODEOWNERS via a setting in GitHub. It would be great if you can annotate a listing in CODEOWNERS that the review is optional for certain folders...

"/build/logs/ @user #required=false"

[willnorris]

As a separate request, but closely related so I'll include it here...

At Google, our internal code ownership system requires at least 1 reviewer, as well as either the author or reviewer of the commit being an owner of the code. As I understand it, if you enable "Require review from Code Owners", then it actually has to be the reviewer who is an owner. This becomes problematic for projects that don't have very many owners.

So the concrete feature request would be to modify "Require review from Code Owners" to allow this to be satisfied by the code author being an owner (not just the reviewer).

[jeffmcaffer]

+1