-----------------
* Added MetricConfusionMatrixBase for adding custom confusion matrix based metrics
* Added ConfusionMatrixBasedMetric Enum to get specific metrics such as tp,fp,fn,tn,precision,sensitivity,specificity,recall,ppv,npv,accuracy,f1score
* Added confusion matrix common metrics (TruePositives, TrueNegatives, FalsePositives, FalseNegatives)
* Added MetricMethod enum to pass to MetricBase, now you can define whether your metric is based on MEAN, SUM or LAST of all batches
* StatsPrint callback now support "print_confusion_matrix" and "print_confusion_matrix_normalized" arguments in case MetricConfusionMatrixBase metric is found
* Added confusion matrix tests and example
* Some custom layers renames (breaking changes in this part)