Five days before every major star of Saturday Night Live past and present was set to descend upon the iconic stage to celebrate the show’s 40th anniversary, Louie Zakarian was getting a little nervous. Scripts for the star-packed Sunday night production — which will see returns from more than two dozen former cast members and a number of the show’s most prolific guest hosts — were just starting to come in, and Zakarian, head of the show’s makeup department, knew that before them was a task of incredible proportions. For 20 years — half of the show’s existence — the New York native has overseen the makeup department at Saturday Night Live, a job that could mean doing old age makeup on a half dozen cast members on one day and figuring out how to turn Andy Samberg from Na’vi to not in less than four