Let’s continue reexporting jid and minidom, but not their inner pub
items, users of this crate can go one level deeper if they need that.
Only xso::error::Error is still useful to reexport, as this is part of
the public API of all of our parsers.
This depends on XEP-0313 for its MAM metadata, and many others such as
XEP-0198, XEP-0280 and XEP-0352 for the inline features, but we
currently provide those as minidom Elements instead.
