On rare occasion as a theater critic do I see a production that calls less for a review and more for a doctorate dissertation, but Jackie Sibblies Drury’s We Are Proud to Present a Presentation About the Herero of Namibia, Formerly Known as South-West Africa, From the German Sudwestafrika, Between the Years 1884-1915 at Stages Repertory Theatre (now through April 1) feels like such a play.