citeproc changes allow us to ignore Quoted elements;
citeproc now uses its own method for represented quoted
things, and only localizes and flipflops quotes it adds itself.
See #87.
The one thing left to do is to convert Quoted elements in
bibliography databases (esp. titles) to `Span ("",["csl-quoted"],[])`
before passing them to citeproc, IF the localized quotes
for the quote type match the standard inverted commas.
