Update to 1.839
    
    - New upstream release 1.839
      - Seeds the Math::Random::MT::Auto generator automatically when present in
        MCE::Hobo, similarly to Math::Random and Math::Prime::Util, to avoid child
        processes sharing the same seed value as the parent and each other; the new
        seed is computed using the current seed
      - Updated MCE::Shared::Cache to support optional argument "expires_in" for
        set and sugar methods
      - Updated MCE::Shared documentation
      - Bumped MCE dependency to 1.837