Added support for training of an already trained model

MLP/include/MLP.hpp

MLP/src/MLP.cpp

decoder/src/macaon_decode.cpp

maca_common/include/util.hpp

maca_common/src/Dict.cpp

maca_common/src/util.cpp

trainer/include/TrainInfos.hpp

trainer/include/Trainer.hpp

trainer/src/TrainInfos.cpp

trainer/src/Trainer.cpp

trainer/src/macaon_train.cpp

transition_machine/src/Classifier.cpp