Introduce an extra flag for processing annotated text which makes the default behavior catch all available text.

Before, it stopped on the first unknown element, as it is desired on paragraph level.
Do not claim to have processed corresp in contributor properties.

The corresp element very often contains much more than just an email address.
We could either extend the contributor node to contain everything a corresp
might provide (full-fledged address information), or just leave it as an author-note.