After a dramatic day in the San Francisco urban jungle, a ring-tailed lemur has been returned to the zoo from where he went missing earlier this week. And the zoo has a sprightly 5-year-old boy to thank for his safe recovery.Maki, a 21-year-old ring-tailed lemur who wears a perpetually alarmed expression on his petite face, was returned to the San Francisco Zoo on Thursday. Daly