(For Wed. M.E.) The year-round school movement is picking up speed in Saint Paul. Saint Paul and five suburban districts opened a new year-round middle school yesterday. Most of the students came from two existing year-round elementary schools. Another year-round elementary is scheduled to open in Saint Paul next fall. Parents are pushing for the schools because they say they're convinced the alternative calendar means better education for their children. Minnesota Public Radio's Tim Pugmire reports... Students at Interdistrict Middle School take turns climbing a step ladder to pour cups of various-sized rocks into a long plastic tube. When it's finished, the tube will decorate the school hallways. Teacher Ron Schl