Using draft-comment in table breaks the word output

[raducoravu]

Related to #71 as draft comments are not supposed to be visible by default anyway.
Attached a sample, inside a table entry I have a fig which contains a draft-comment inside a paragraph:

                    <entry align="left" valign="top" colsep="0" rowsep="0">
                        <fig>
                            <title>Fig</title>
                            <p>
                                <draft-comment author="author">Image updated</draft-comment>
                            </p>
                        </fig>
                    </entry>

flowers.zip

The generated word document can no longer be opened and is invalid.