By Denny Dyroff, Staff Writer, The Times Selwin Birchwood Selwyn Birchwood is one of the brightest new stars to emerge in the world of blues music in recent years. And, he will be one of the brightest stars at this weekend’s Riverfront Blues & BBQ Festival (Tubman-Garrett Park, Wilmington, Delaware, 302-576-2139, http://riverfrontbluesfestde.com/) with a performance on August 7. In 2013,...