Making app.classify.backend more generic; now there is only one linear example and its efficient.
app.classify.backend: refactoring the training interface to make it more generic
Merge pull request #90 from alextp/refactor-backend-classify

Refactor backend classify
app.nlp.mention: fixing bug in parse based mention finding
app.nlp.lemma: fixing lower case lemmatizer to be consistent with its attributes
app.nlp.coref: fixing coref bug
Created Chain Chunker with BILOU encoding for conll 2000.
Merge branch 'master' of https://github.com/factorie/factorie