Merge branch 'js/range-diff-wo-dotdot'

There are other ways than ".." for a single token to denote a "commit range", namely "<rev>^!" and "<rev>^-<n>", but "git range-diff" did not understand them. * js/range-diff-wo-dotdot: range-diff(docs): explain how to specify commit ranges range-diff/format-patch: handle commit ranges other than A..B range-diff/format-patch: refactor check for commit range