“Mary Poppins” was first released in 1964, and nothing can top Julie Andrews singing, dancing and flying away in a magical umbrella. And it looks like the creators of this year’s “Mary Poppins Returns,” starring Emily Blunt as the enchanting nanny, understand that: “Supercalifragilisticexpialidocious” won’t be a number in this sequel. Director Rob Marshall said that they wanted to preserve that word in the original film, since it's so synonymous with that cast.