* Add ReutersTrainer, ReutersEvaluator options in Factory classes
* Add Reuters to Kim-CNN command line arguments
* Fix SST dataset path according to changes in Kim-CNN args
The dataset path in args.py was made to point at the dataset folder rather than dataset/SST folder. Hence SST folder was added to paths in the SST dataset class
* Add Reuters dataset class, and support in __main__
* Add Reuters dataset trainers and evaluators
* Remove debug print statement in reuters_evaluator
* Fix rounding bug in reuters_trainer and reuters_evaluator
* Refactor datasets
* Update evaluators
* Update trainers
* Update main and MP-CNN model
* Add serialization util
* Fix bugs
* Refactoring for NCE to use new parent class