M. Cacciari, S. Frixione, M. Mangano, P. Nason, and G. Ridolfi. (2008)cite arxiv:0804.2800
Comment: Updated description of comparison with 0804.1476. Improvements in
text and update of published references. No changes in results. Version to
appear in JHEP. v3 fixes a typo in the authors' list.
S. Alioli, P. Nason, C. Oleari, and E. Re. (2009)cite arxiv:0907.4076
Comment: Figs. 10, 11 and 12 were obtained without the acceptance cuts
described in the text. They have been replaced with the correct ones.