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