Institute of Bioinformatics, Department of Informatics, Ludwig-Maximilians-Universität München, Amalienstrasse 1780333, Munich, Germany. Ludwig.Geistlinger@bio.ifi.lmu.de.|Institute of Bioinformatics, Department of Informatics, Ludwig-Maximilians-Universität München, Amalienstrasse 1780333, Munich, Germany. Gergely.Csaba@bio.ifi.lmu.de.|Institute of Bioinformatics, Department of Informatics, Ludwig-Maximilians-Universität München, Amalienstrasse 1780333, Munich, Germany. Ralf.Zimmer@bio.ifi.lmu.de.