Today, by a unanimous vote, the D.C. Council approved amendments to a medical marijuana law first passed in 1998 by 69 percent of District voters. Congress had blocked implementation of Initiative 59 for more than a decade, until it lifted its ban last year. Mayor Adrian Fenty is expected to sign the bill, at which point Congress will have 30 days to review before it becomes law. Once that happens, the District of Columbia will join 14 states across the country in allowing qualified patients to use…