- Split conditional processing, footnotes, document inclusion, LaTeX-specific ...

elements, maths, meta-elements, native code processing and Otago-specific
  elements into separate modules.
- Moved centering into basic text formatting module.

- Spilt basic text formatting, code formatting, font and typeface control, ...

and quoted text elements off into separate modules.
- Moved non-breakable text and vskip elements into basic page elements module.