Puritan-style laws have long been the bane of Boston’s nightlife scene – especially since the last T subway trains leave the station at 1 a.m. on weekends. Happily, that’s all about to change. Come spring, all T routes and select bus routes will extend their late night service to 3 a.m. on Fridays and Saturdays during a one-year pilot program. In anticipation, we rustled up five fun ideas for what to do in Boston after the clock strikes 12…Puritan-style laws have long been the bane of Boston’s nightlife scene – especially since the last T subway trains leave the station at 1 a.m. on weekends. Happily, that’s all about to change. Come spring, all T routes and select bus routes will extend their late night service to 3 a.m. on Fridays and Saturdays during a one-year pilot program. In anticipation, we rustled up five fun ideas for what to do in Boston after the clock strikes 12…