Updated Redactor to fit ace data

Redactor now uses task and task variant to determine which views to cleanse.
For everything except Gold Tokens, Redactor removes all views except SENTENCE and TOKENS.
For NER Gold Tokens, Redactor keeps the NER_GOLD_EXTENT_SPAN view, but removes the labels.
For Relation Extraction, Redactor keeps the RELATIONVIEW, removes the relations, and keeps the constituents.
For Coreference, Redactor keeps the COREF view, removes the relations, and keeps the constituents.

CogComp / open-eval