Legalization of Recreational Marijuana; Authorizes persons age 21 & over to engage in certain activities involving personal use of marijuana in limited amounts; provides limits on where persons may engage in specified activities; provides for licensure of marijuana establishments; provides limits on number of retail marijuana stores in localities; specifies that chapter does not apply to employer drug policies or operating under influence laws; removes cannabis from schedule of controlled substances; removes restrictions of possession & sale of cannabis; provides for retroactive effect; provides for sentencing review for certain offenders.