1) added a new class PrentTagProvider (authored by Thomas), added PrentTagProvider variable and a new method initParentTagProvider() (authored by Thomas) into UnsupervisedClauseMarkup class. 2) Added a utility method getSource() (authored by Thomas). 3) added use of getSource() into methods readWordToSources(), readSentenceTags(), readSentencesForOrganStateMarker().