Concerning the "Workers' Compensation Act of Colorado", and, in connection therewith, making changes that affect the timely payment of benefits, guardian ad litem and conservator services, benefit offsets related to the receipt of federal disability or retirement benefits, the reduction of benefits based on apportionment, the selection of independent medical examiners, limits on temporary disability and permanent partial disability payments, the withdrawal of admissions of liability, mileage expense reimbursement, the authority of prehearing administrative law judges, the reopening of permanent total disability awards, and petitions for review and appeals of orders.