Classes and methods for mapping one part of speech tag set to another.

All MorphAdorner part of speech mappers must implement the {@link edu.northwestern.at.morphadorner.corpuslinguistics.partsofspeech.mapper.PartOfSpeechTagsMapper} interface. The {@link edu.northwestern.at.morphadorner.corpuslinguistics.partsofspeech.mapper.PartOfSpeechTagsMapperFactory} provides the mechanism for instantiating a default or specified instance of a PartOfSpeechTagsMapper implementation. The {@link edu.northwestern.at.morphadorner.corpuslinguistics.partsofspeech.mapper.AbstractPartOfSpeechTagsMapper} serves as a base class for deriving concrete implementations of part of speech tag mappers.