Add built-in citation support using new citeproc library.

This deprecates the use of the external pandoc-citeproc
filter; citation processing is now built in to pandoc.

* Add dependency on citeproc library.
* Add Text.Pandoc.Citeproc module (and some associated unexported
  modules under Text.Pandoc.Citeproc).  Exports `processCitations`.
  [API change]
* Add data files needed for Text.Pandoc.Citeproc:  default.csl
  in the data directory, and a citeproc directory that is just
  used at compile-time.  Note that we've added file-embed as a mandatory
  rather than a conditional depedency, because of the biblatex
  localization files. We might eventually want to use readDataFile
  for this, but it would take some code reorganization.
* Text.Pandoc.Loging: Add `CiteprocWarning` to `LogMessage` and use it
  in `processCitations`. [API change]
* Add tests from the pandoc-citeproc package as command tests (including
  some tests pandoc-citeproc did not pass).
* Remove instructions for building pandoc-citeproc from CI and
  release binary build instructions.  We will no longer distribute
  pandoc-citeproc.
* Markdown reader: tweak abbreviation support.  Don't insert a
  nonbreaking space after a potential abbreviation if it comes right before
  a note or citation.  This messes up several things, including citeproc's
  moving of note citations.
* Add `csljson` as and input and output format. This allows pandoc
  to convert between `csljson` and other bibliography formats,
  and to generate formatted versions of CSL JSON bibliographies.
* Add module Text.Pandoc.Writers.CslJson, exporting `writeCslJson`. [API
  change]
* Add module Text.Pandoc.Readers.CslJson, exporting `readCslJson`. [API
  change]
* Added `bibtex`, `biblatex` as input formats.  This allows pandoc
  to convert between BibLaTeX and BibTeX and other bibliography formats,
  and to generated formatted versions of BibTeX/BibLaTeX bibliographies.
* Add module Text.Pandoc.Readers.BibTeX, exporting `readBibTeX` and
  `readBibLaTeX`. [API change]
* Make "standalone" implicit if output format is a bibliography format.
  This is needed because pandoc readers for bibliography formats put
  the bibliographic information in the `references` field of metadata;
  and unless standalone is specified, metadata gets ignored.
  (TODO: This needs improvement. We should trigger standalone for the
  reader when the input format is bibliographic, and for the writer
  when the output format is markdown.)
* Carry over `citationNoteNum` to `citationNoteNumber`.  This was just
  ignored in pandoc-citeproc.
* Text.Pandoc.Filter: Add `CiteprocFilter` constructor to Filter.
  [API change] This runs the processCitations transformation.
  We need to treat it like a filter so it can be placed
  in the sequence of filter runs (after some, before others).
  In FromYAML, this is parsed from `citeproc` or `{type: citeproc}`,
  so this special filter may be specified either way in a defaults file
  (or by `citeproc: true`, though this gives no control of positioning
  relative to other filters).  TODO: we need to add something to the
  manual section on defaults files for this.
* Add deprecation warning if `upandoc-citeproc` filter is used.
* Add `--citeproc/-C` option to trigger citation processing.
  This behaves like a filter and will be positioned
  relative to filters as they appear on the command line.
* Rewrote the manual on citatations, adding a dedicated Citations
  section which also includes some information formerly found in
  the pandoc-citeproc man page.
* Look for CSL styles in the `csl` subdirectory of the pandoc user data
  directory.  This changes the old pandoc-citeproc behavior, which looked
  in `~/.csl`.  Users can simply symlink `~/.csl` to the `csl`
  subdirectory of their pandoc user data directory if they want
  the old behavior.
* Add support for CSL bibliography entry formatting to LaTeX, HTML,
  Ms writers.  Added CSL-related CSS to styles.html.

1 files changed, 111 insertions, 0 deletions

diff --git a/test/command/pandoc-citeproc-chicago-author-date.md b/test/command/pandoc-citeproc-chicago-author-date.md
new file mode 100644
index 000000000..2840f4435
--- /dev/null
+++ b/test/command/pandoc-citeproc-chicago-author-date.md
@@ -0,0 +1,111 @@
+```
+% pandoc --citeproc -t markdown-citations
+---
+bibliography: command/biblio.bib
+link-citations: true
+---
+
+Pandoc with citeproc-hs
+=======================
+
+[@nonexistent]
+
+@nonexistent
+
+@item1 says blah.
+
+@item1 [p. 30] says blah.
+
+@item1 [p. 30, with suffix] says blah.
+
+@item1 [-@item2 p. 30; see also @пункт3] says blah.
+
+In a note.[^1]
+
+A citation group [see @item1 chap. 3; also @пункт3 p. 34-35].
+
+Another one [see @item1 p. 34-35].
+
+And another one in a note.[^2]
+
+Citation with a suffix and locator [@item1 pp. 33, 35-37, and nowhere
+else].
+
+Citation with suffix only [@item1 and nowhere else].
+
+Now some modifiers.[^3]
+
+With some markup [*see* @item1 p. **32**].
+
+References {#references .unnumbered}
+==========
+
+[^1]: @пункт3 [p. 12] and a citation without locators [@пункт3].
+
+[^2]: Some citations [see @item1 chap. 3; @пункт3; @item2].
+
+[^3]: Like a citation without author: [-@item1], and now Doe with a
+    locator [-@item2 p. 44].
+^D
+[WARNING] Citeproc: citation nonexistent not found
+Pandoc with citeproc-hs
+=======================
+
+([**nonexistent?**](#ref-nonexistent))
+
+([**nonexistent?**](#ref-nonexistent))
+
+[Doe](#ref-item1) ([2005](#ref-item1)) says blah.
+
+[Doe](#ref-item1) ([2005, 30](#ref-item1)) says blah.
+
+[Doe](#ref-item1) ([2005, 30](#ref-item1), with suffix) says blah.
+
+[Doe](#ref-item1) ([2005](#ref-item1), [2006, 30](#ref-item2); see also
+[Doe and Roe 2007](#ref-пункт3)) says blah.
+
+In a note.[^1]
+
+A citation group (see [Doe 2005, chap. 3](#ref-item1); also [Doe and Roe
+2007, 34--35](#ref-пункт3)).
+
+Another one (see [Doe 2005, 34--35](#ref-item1)).
+
+And another one in a note.[^2]
+
+Citation with a suffix and locator ([Doe 2005, 33, 35--37](#ref-item1),
+and nowhere else).
+
+Citation with suffix only ([Doe 2005](#ref-item1) and nowhere else).
+
+Now some modifiers.[^3]
+
+With some markup (*see* [Doe 2005, 32](#ref-item1)).
+
+References {#references .unnumbered}
+==========
+
+::: {#refs .references .csl-bib-body .hanging-indent}
+::: {#ref-item1 .csl-entry}
+Doe, John. 2005. *First Book*. Cambridge: Cambridge University Press.
+:::
+
+::: {#ref-item2 .csl-entry}
+---------. 2006. "Article." *Journal of Generic Studies* 6: 33--34.
+:::
+
+::: {#ref-пункт3 .csl-entry}
+Doe, John, and Jenny Roe. 2007. "Why Water Is Wet." In *Third Book*,
+edited by Sam Smith. Oxford: Oxford University Press.
+:::
+:::
+
+[^1]: [Doe and Roe](#ref-пункт3) ([2007, 12](#ref-пункт3)) and a
+    citation without locators ([Doe and Roe 2007](#ref-пункт3)).
+
+[^2]: Some citations (see [Doe 2005, chap. 3](#ref-item1); [Doe and Roe
+    2007](#ref-пункт3); [Doe 2006](#ref-item2)).
+
+[^3]: Like a citation without author: ([2005](#ref-item1)), and now Doe
+    with a locator ([2006, 44](#ref-item2)).
+```