The last hurdle that could have stalled DeKalb's new superintendent from taking the reins of Georgia's third largest school district is now cleared. Cheryl L. H. Atkinson, who was the superintendent of Lorain City Schools near Cleveland, Ohio, was released from her contract by her school board this week. That step was necessary before Atkinson could start her $275,000-a-year job as DeKalb's top school official. She is expected to start on or before Sept. 15. She was selected after a 2-year search for the district that has about 96,000 students.