moved add2HeuristicNounTable() from Learner class to DataHodler class.
1) fixed a bug in getKnownTags(). 2) change Sentence to Token.
Change Sentence to Token, UnsupervisedLearningTokenizer to OpenNLPTokenizer, UnsupervisedLearningSentenceDetector to OpenNLPSentencesTokenizer. 2) overrided equals() in Token class. 3) some code clean up.
created a new package semanticMarkup.ling.learn.dataholder. moved related classes into the package.