1. Department of Astrophysics/IMAPP, Radboud University, P.O. Box 9010, NL-6500 GL Nijmegen, the Netherlands
2. Department of Astronomy, University of Cape Town, Private Bag X3, 7701 Rondebosch, South Africa
3. South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town, South Africa
4. The Inter-University Institute for Data Intensive Astronomy, University of Cape Town, Private Bag X3, 7701 Rondebosch, South Africa