There are changes afoot for Glee next season — we’ve already learned that the show is moving to Thursdays and will welcome Kate Hudson and Sarah Jessica Parker — but how will it deal with the graduating seniors? According to Fox’s Kevin Reilly, Glee will “adopt a show-within-a-show†format that follows the action at both the performing arts school in New York and back at William McKinley High, where even more new cast members will join New Directions. Is there such a thing as a “spin-in�