HAMA-770: finishes AbstractLayeredNeuralNetwork
HAMA-770: revise TestSmallMultiLayerPerceptron
HAMA-770: add test case to TestSmallLayeredNeuralNetwork
add readFields and write to NeuralNetwork
HAMA-770: update readFields and write
HAMA-770: add test case for TestSmallNeuralNetwork
HAMA-770: add test case for TestSmallLayeredNeuralNetwork