Brixton House, LondonDirector Monique Touko keeps the tone lively with this tough story of Mugabe's Zimbabwe in which the actors switch race, age and gender with ease In a place called Paradise a raggle-taggle bunch of children scrump guavas and gambol about in the dust. They are 10 and 11 years old and Chipo, so traumatised she can barely speak, is pregnant. This is Robert Mugabe's Zimbabwe and it is far from paradi…