Modifying certain provisions relating to the public employees retirement association (PERA); defining and redefining certain terms; modifying the determination of included employees and employee exclusions; providing for optional membership for certain classes of public employees; clarifying the definition of salary; modifying the procedures for deducting employee contributions and omitted salary deductions from salary and certain employer salary deduction and exclusion reporting requirements, requiring the reporting of compensated hours; modifying eligibility for and exclusions from membership in the public employees police and fire fund (ra)