Bioinformatics Research Center, Department of Computer Science, University of Aarhus, Høegh-Guldbergs Gade 10, Building 090, DK-8000 Arhus C, Denmark. besen@daimi.au.dk|Bioinformatics Research Center, Department of Computer Science, University of Aarhus, Høegh-Guldbergs Gade 10, Building 090, DK-8000 Arhus C, Denmark. besen@daimi.au.dk|Bioinformatics Research Center, Department of Computer Science, University of Aarhus, Høegh-Guldbergs Gade 10, Building 090, DK-8000 Arhus C, Denmark. besen@daimi.au.dk|Bioinformatics Research Center, Department of Computer Science, University of Aarhus, Høegh-Guldbergs Gade 10, Building 090, DK-8000 Arhus C, Denmark. besen@daimi.au.dk