add support for parsing JATS files

[nuest]

The Journal Article Tag Suite (JATS) is an XML format used to describe scientific literature published online. https://en.wikipedia.org/wiki/Journal_Article_Tag_Suite

For example, extract could support the Article Authoring Tag Set.

JATS could allow good integration with existing publishing systems.

Resources:

• https://jats.nlm.nih.gov/
• http://blog.martinfenner.org/2014/03/03/six-misunderstandings-about-scholarly-markdown/
• http://blog.martinfenner.org/2013/12/12/from-markdown-to-jats-xml-in-one-step/

[ghost]

We have already discussed this over one year ago and decided against it. I think it was because it was impossible to determine if this is in widespread use. My tendency would be to discard it, at least for as long as my legislature over this repository has come to an end, given the large list of important other tasks.

[nuest]

If "discard" means that we leave the issue here, then that's fine. Next time I think about JATS I will find this issue and know we've already discussed it.