Department of Computer Science, University of Waikato, Private Bag 3105, Hamilton, New Zealand. eibe@cs.waikato.ac.nz|Department of Computer Science, University of Waikato, Private Bag 3105, Hamilton, New Zealand. eibe@cs.waikato.ac.nz|Department of Computer Science, University of Waikato, Private Bag 3105, Hamilton, New Zealand. eibe@cs.waikato.ac.nz|Department of Computer Science, University of Waikato, Private Bag 3105, Hamilton, New Zealand. eibe@cs.waikato.ac.nz|Department of Computer Science, University of Waikato, Private Bag 3105, Hamilton, New Zealand. eibe@cs.waikato.ac.nz