Make M-x authors return zero *Authors Errors* from current logs

Make M-x authors return zero *Authors Errors* from current logs

* lisp/emacs-lisp/authors.el (authors-obsolete-files-regexps):
(authors-ignored-files): Add some entries, remove others.
(authors-ambiguous-files, authors-valid-file-names): Add some entries.
(authors-renamed-files-alist): Add, remove, and adjust entries.
(authors-renamed-files-regexps): Add some entries.
Remove some very broad ones.  Make some entries `lax'.
(authors-lax-changelogs): New constant.
(authors-disambiguate-file-name): Treat top-level specially.
(authors-lax-changelog-p): New function.
(authors-canonical-file-name): Check file as written against
authors-valid-file-names.  Do not special-case etc/.
Handle `lax' logs and authors-renamed-files-regexps elements.

* admin/make-tarball.txt: Update for no expected *Authors Errors*.