Excluding legislators elected after a certain date from the legislators retirement plan under the Minnesota state retirement system, providing for social security coverage for the legislators, requiring the governor to enter an agreement with the federal secretary of health and human services to extend the benefits of the federal old age, survivors and disability insurance system to the legislators; authorizing legislators elected prior to the date to opt out of the legislators retirement plan and elect to be covered by social security, requiring the director of MSRS upon request of the legislator to transfer contributions to the appropriate fund (je)