Merge branch 'ma/shortlog-revparse'

"git shortlog cruft" aborted with a BUG message when run outside a Git repository. The command has been taught to complain about extra and unwanted arguments on its command line instead in such a case. * ma/shortlog-revparse: shortlog: disallow left-over arguments outside repo shortlog: add usage-string for stdin-reading git-shortlog.txt: reorder usages