East Village canine cafe Boris & Horton will host romantic dinners for New Yorkers whose love lives have gone to the dogs. The intimate owner-doggie date night , which is set for Saturday from 5:30 to 7 pm, will feature prix fixe menus designed for both humans and their pooches. The “Love at First Bark” dinner has more than 50 reservations of diners either bringing their dogs as their dates or couples bringing along their beloved pet. “Valentine’s Day is all about love. It’s all about