If you are staying in town over Memorial Day weekend, be sure to catch some of the new and closing exhibits at the end of this month. Keep reading for the highlights. >> “A Collection in Formation: 1975-2005” opens today at the Federal Reserve Board (you didn’t know that they have an art collection, did you?). The exhibit features the best work from the 30-year-old collection of American paintings, drawings and prints. One painting from…