Affiliations were `xlink`ed even in the articleauthoring tag set, but
`<aff>` are not allowed as children of `contrib-group` elements in that
tag set. Each affiliation must be listed directly in the contrib
element.
The partitioning the components of a name into surname, given names,
etc. is not always possible or not available. Using `author.name` allows
to give the full name as a fallback to be used when `author.surname` is
not available.
New formats:
- `jats_archiving` for the "Archiving and Interchange Tag Set",
- `jats_publishing` for the "Journal Publishing Tag Set", and
- `jats_articleauthoring` for the "Article Authoring Tag Set."
The "jats" output format is now an alias for "jats_archiving".
Closes: #6014
