More than 100,000 remained without power last night as coastal communities throughout the Bay State began the arduous task of cleaning up from the nor’easter that pounded Massachusetts for two days.More than two dozen schools throughout the state canceled classes for today.The MBTA said because of the storm, commuters on the Greenbush, Kingston and Newburyport/Rockport lines should plan on 15 to 20 minutes of potential delays.