Authorizing and providing for school districts to establish choice magnetschools; specifying certain requirements of the choice magnet schools, requiring school boards and exclusive representatives of teachers to agree to a contract waiver to provide a flexible school day for the choice magnet program; modifying the conditions for appeal to the commissioner of children, families and learning of school board decisions not to sponsor charter schools; specifying certain consideration requirements of the commissioner for approval or disapproval of proposed sponsorship authorizations; prohibiting appeal of school board decisions to disapprove the proposed location in the district of charter schools sponsored by the school board of another district; modifying the charter school building lease aid formula and entitling school district sponsored choice magnet schools to start up cost aid (mk)