The Easthampton Committee for Stronger Schools is joining with the city's school committee in a forum Tuesday night about a proposed property tax override to fund schools.  Spokesman Marin Goldstein supports Question Four on the Easthampton balot, which calls for the override.  He says it's needed to restore programs and school positions.  Residents can learn more at the forum at 50 Payston Avenue, beginning at 7 p.m.