Docx reader: add failing tests for inline code and code blocks.
Docx reader: pass code tests.
Docx Reader: add failing defintion list tests.
Docx reader: pass definition test.

This commit also fixes a problem with the previous code pushes, which
wouldn't allow code blocks to share a div.
Docx reader: remove T.P.Generic import.

This marks the removal of the final tree-walk in the code. (Though there
is still one in the Lists module.)
Merge pull request #1368 from jkr/docxCode

Docx verbatim code formatting
Docx reader: Ignore zero (or negative) indent

If a block has an indentation less than or equal to zero, it should not be
treated as a block quote.
Merge pull request #1370 from jkr/fix-zero-indent

Docx reader: Ignore zero (or negative) indent
Docx Reader: Add change types

Insertion and deletion. Dates are just strings for now.
Docx reader: Parse Insertions and Deletions.

This is just for the Parse module, reading it into the Docx format. It
still has to be translated into pandoc.
Docx reader: Add rudimentary track changes support.

This will only read the insertions, and ignore the deletions.
Docx reader: Remove unnecessary filter in Parse.

mapMaybe does the filtering for us.
Docx reader: Add tests for basic track changes

This is what seems like the sensible default: read in insertions, and
ignore deletions. In the future, it would be good if options were
available for either taking in deletions or keeping both in some
scriptable format.
Add TrackChanges type to options.
Add reader option for track changes.
Add TrackChanges to Options export.
Add track changes option to command line.
Docx reader: Make use of track-changes option.
Merge pull request #1372 from jkr/track-changes

Rudimentary track-changes support
Updated README to include "--track-changes" option.