WIP: Make emitter work with Open XML (issue #4)

This is still work in progress. We can probably get away with
simplifying the namespace / schema section by using the official
MAML markup for bold and italic and simply use a paragraphs to
separate them instead of a <br/> tag.

However, for the images in the table we absolutely need a <nobr>
tag. Otherwise the images will look terrible in the regular HTML
output. We should either find a way to make them valid for Open
XML or pass the presentation style through to the context object
so that we can special case this.