DVRs are set for tonight’s 100th episode of Gossip Girl, the little show that conquered an entire zip code and age group and kick-started an accessory trend or two. We caught up with Stephanie Savage, the show’s co-creator, writer and executive producer, to talk spoilers and Gossip Girl’s 9th character — New York City. See the feature… See the show at 8 pm ET o the CW.