KTH Royal Institute of Technology, School of Computer Science and Communication, Box 1031, Solna, 171 21, Sweden.|KTH Royal Institute of Technology, School of Computer Science and Communication, Box 1031, Solna, 171 21, Sweden.|KTH Royal Institute of Technology, School of Computer Science and Communication, Box 1031, Solna, 171 21, Sweden.|Science for Life Laboratory, Box 1031, Solna, 171 21, Sweden.|KTH Royal Institute of Technology, School of Computer Science and Communication, Box 1031, Solna, 171 21, Sweden. jensl@kth.se.