v0.8.17

Two papers came out of the split with no front matter, and this gives it
back to them.

The RSA paper has no numbered sections that the splitter recognises, so
the appendix scan had no last heading to start after and began at
paragraph one. It read the paper's own title as appendix A, which took
the title away from the front matter. The scan now returns nothing when
there are no body headings at all, because an appendix comes after the
body and a paper with no body has nowhere to put one.

The AlphaGo paper prints the word ARTICLE over the title, and a reader
transcribes that as a heading like everything else set large. The title
was only compared against the first heading, so the masthead stayed and
took the title, the authors and the abstract into section one. The title
is now looked for over the first three headings, and the search stops at
the first heading that carries a number of its own so that a paper whose
section one is named after the paper keeps it.

What's Changed

• Give two papers back their front matter by @tamnd in #227

Full Changelog: v0.8.16...v0.8.17