Boston, MA 11/22/11 Principal Jeichael K. Henderson (cq) sees kindergarteners (in K-2 room A102) off to lunch. He gives The Boston Globe a tour of the John P. Holland School, on Tuesday, November 22, 2011. The Dorchester school has a number of facility perks and is making changes to improve its academic programs. (Pat Greenhouse/Globe Staff); Reporter: Vaznis; Section: Metro; Slug: XXX