Backpropagation

Backpropagation finished, getOutput added, Neuron class removed.
Merge branch 'OCR-NN-2' of https://github.com/Mith/THO7-LicenseRecognition into OCR-NN-2

Conflicts:
	OCR NN 2/NeuralNetwork.cpp
	OCR NN 2/NeuronLayer.cpp
	OCR NN 2/NeuronLayer.h
Merge edits

Simon's edit's merged with my update