Stack to Images processes slices out of order

[afraser]

This could be a concern for people who've written macros that assume the windows returned by this command are in order.

To reproduce:
open Bat Cochlea Renderings
Image > Stacks > Tools > Make Substack

--range: 1-10

Image > Stacks > Stack to Images

The slice numbering is correct, but the slices are processed out of order.