Centre for Systems and Synthetic Biology, Department of Computer Science, Royal Holloway, University of London, TW20 0EX, Egham, UK. tamas@cs.rhul.ac.uk|Centre for Systems and Synthetic Biology, Department of Computer Science, Royal Holloway, University of London, TW20 0EX, Egham, UK. tamas@cs.rhul.ac.uk|Centre for Systems and Synthetic Biology, Department of Computer Science, Royal Holloway, University of London, TW20 0EX, Egham, UK. tamas@cs.rhul.ac.uk