This method has to be called from the XSL style sheet from within the word template, BEFORE the call to
getEndedMarkables() (if any)! This order is important because markable handles are supposed to
end AFTER the actual word string.
This method has to be called from the XSL style sheet from within the word template, AFTER the call to
getStartedMarkables() (if any)! This order is important because markable handles are supposed to
begin BEFORE the actual word string.
For each fragment this Markable contains, this method sets the associated display positions in displayStart- and
displayEndPosition, by setting displayStartPositions, displayEndPositions, discourseElementStartPositions,
leftmostDisplayPosition, rightmostDisplayPosition.