need feedback from implementors (in particular Zotero and Mendeley)

Two tricky issues where RIntze and I aren’t entirely on the same page,
and so need feedback on:

https://github.com/citation-style-language/schema/issues/50
https://github.com/citation-style-language/schema/issues/72

Please register your opinions on each. I see #50 as in part how we
deal with tensions between authoring styles and publishing them, and
#72 as how we deal with schema bugs (which we have here).

Bruce