Update tests.
Reason: it turns out that the native output generated by
pretty-simple isn't always readable by the native reader.
According to https://github.com/cdepillabout/pretty-simple/issues/99
it is not a design goal of the library that the rendered values
be readable using 'read'. This makes it unsuitable for our
purposes.
pretty-show is a bit slower and it uses 4-space indents
(non-configurable), but it doesn't have this serious drawback.
Previously we used our own homespun formatting. But this
produces over-long lines that aren't ideal for diffs in tests.
Easier to use something off-the-shelf and standard.
Closes#7580.
Performance is slower by about a factor of 10, but this isn't
really a problem because native isn't suitable as a serialization
format. (For serialization you should use json, because the reader
is so much faster than native.)
Previously, using `--citeproc` could cause punctuation to move in
quotes even when there aer no citations. This has been changed;
now, punctuation moving is limited to citations.
In addition, we only move footnotes around punctuation if the
style is a note style, even if `notes-after-punctuation` is `true`.
This affected author-in-text citations in footnotes.
It didn't cause problems for the printed output, but for
filters that expected the citation id and other information.
Closes#6890.
