London’s Royal Ballet tries to revive a glorious past with “Sleeping Beauty.” “Nostalgia is the key word, and American audiences are probably fortunate to have less of it, in regard to this production, than English ballet lovers. The English have fussed over this ballet, and this production, for 60 years now. Would it hamper the company if it were addicted to the popular, big-production story ballets? Can the company grow if it is constantly looking back to a rose-tinted vision of the past?”