Added base class to neural network

decoder/src/Decoder.cpp

reading_machine/include/Classifier.hpp

reading_machine/include/Config.hpp

reading_machine/src/Classifier.cpp

reading_machine/src/Config.cpp

torch_modules/include/ConcatWordsNetwork.hpp

torch_modules/include/NeuralNetwork.hpp

torch_modules/include/OneWordNetwork.hpp

torch_modules/src/ConcatWordsNetwork.cpp

torch_modules/src/NeuralNetwork.cpp

torch_modules/src/OneWordNetwork.cpp

trainer/include/Trainer.hpp

trainer/src/Trainer.cpp