Multi-line quotes break on conversion after split

[hcayless]

If a <q> happens to span lines and the splitting process splits inside the quote, then Leiden+ conversion breaks. This may be a tough one to solve for the splitter, given that there's no way to tell a start quote from an end quote other than counting, and split chunks aren't aware of each other. It might be far easier to use "smart" quotes (“”) instead, because they balance properly, maybe even Guillemets («») in addition.

It's probably possible to work around this if smart quotes are undesirable, but tricky....