Pydocx

- Some inline tags
(most notably the underline tag)
could have a ``val`` of ``none``
and that would signify that the style is disabled.
A ``val`` of ``none`` is now correctly handled.

- It is possible for a docx file to not contain a ``numbering.xml`` file
but still try to use lists.
Now if this happens all lists get converted to paragraphs.

- Not all docx files contain a ``styles.xml`` file.
We are no longer assuming they do.

- It is possible for ``w:t`` tags to have ``text`` set to ``None``.
This no longer causes an error when escaping that text.

- In the event that ``cElementTree`` has a problem parsing the document,
a ``MalformedDocxException`` is raised
instead of a
``SyntaxError``

- We were not taking into account that vertical merges should have a continue attribute,
but sometimes they do not,
and in those cases word assumes the continue attribute.
We updated the parser to handle the cases in which the continue attribute is not there.
- We now correctly handle documents with unicode character in the namespace.
- In rare cases,
some text would be output with a style when it should not have been.
This issue has been fixed.