Release v0.3.16

• added console scripts: pww-associator, pww-attsel, pww-classifier, pww-clusterer, pww-datagenerator, pww-filter
• added serialize, deserialize methods to weka.classifiers.Classifier to simplify loading/saving model
• added serialize, deserialize methods to weka.clusterers.Clusterer to simplify loading/saving model
• added serialize, deserialize methods to weka.filters.Filter to simplify loading/saving filter
• added methods plot_rocs and plot_prcs to weka.plot.classifiers module to plot ROC/PRC curve on same dataset
  for multiple classifiers
• method plot_classifier_errors of weka.plot.classifiers module now allows plotting predictions of multiple
  classifiers by providing a dictionary
• method create_instances_from_matrices from module weka.core.dataset now allows string and bytes as well
• method create_instances_from_lists from module weka.core.dataset now allows string and bytes as well