EXECUTIVE OPPORTUNITY   AN INVITATION TO APPLY FOR THE POSITION OF SUPERINTENDENT OF SCHOOLS STONEHAM PUBLIC SCHOOLS, MASSACHUSETTS   The Stoneham, MA School Committee invites future-focused, highly qualified candidates with an educational vision to apply for the position of Superintendent of Stoneham Public Schools.   Stoneham, population 23,300, is a suburban community located nine miles north of Boston; its proximity to major highways and public transportation offers convenient access to Boston and the North S