Visualization Tool

Working with mlpack for almost a year was great. I have always been a fan of the concept see and do. If we can see a graph plotting the accuracy curve while training; would give us more insight and save time instead of actually going through the numbers. Thus I had raised PR for plotting a confusion matrix last year, but still feel we do lack the UI bit in our library. As such, This year I would like to build MLpackBoard so that we can visualize metrics and other utilities.