The city council and all city agencies, boards and commissions are directed to take any and all actions necessary to carry out measure N, including, but not limited to, adoption and implementation of any amendments to the city general plan, zoning ordinance and/or this code. This measure shall be implemented forthwith as a matter of the highest priority of the city. (§ 4 of measure N, passed by voters 11-3-1987: § 15 of proposition R, passed by voters 11-7-1978)