Public Employees Relations Commission; Authorizing subpoenas to be served by certified mail, return receipt requested, or by personal service; revising application requirements for employee organization registration and renewal of registration; providing that a petition to clarify the composition of a bargaining unit may be filed with the commission under certain circumstances; providing that implementation of appropriations from the Legislature which are specifically directed to be disbursed as salaries for employees of local governments are considered a financial urgency; authorizing certain public employers, public employees, and employee organizations, or combinations thereof, to file certain charges with the commission, etc.