Pushing down _normalzationConstants array to threads

[robers97]

The paper shows good scaling to 32 threads. I have been looking at 64, 128, and higher thread counts.
There gets to be some contention in arrays like _normalizationConstants which appears to be suited to live in the body of the thread for all of its life except perhaps the one call to garner statistics.

In addition, in Layer.cpp. this change to loop and then write was beneficial to gcc and helped reduce the sharing contention.

if(_type == NodeType::Softmax) {
    float accum = 0;
    for (int i = 0; i < len; i++) {
        float realActivation = exp(activeValuesperlayer[layerIndex + 1][i] - maxValue);
        activeValuesperlayer[layerIndex + 1][i] = realActivation;
        _Nodes[activenodesperlayer[layerIndex + 1][i]].SetlastActivation(inputID, realActivation);
        accum += realActivation;
    }
    _normalizationConstants[inputID] = accum;
}