A Randomised, Observer-blind, Multicentre, Non-inferiority, Comparative, Phase III Study of the Safety and Efficacy of Topical 1% SB-275833 Ointment, Applied Twice Daily for 5 Days, versus Topical 2% Sodium Fusidate Ointment Applied Three Times Daily for 7 Days in the Treatment of Adult and Paediatric Subjects with Impetigo.