Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany.|Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany.|Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany.|Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany.|Department Computer Science, University of Exeter, Exeter, UK.|Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany.