[3/5] windowscodecs: Create a predefined black&white palette if 1 bpp TIFF image doesn't have one.

[Vincent Povirk]

Are you sure about this? My understanding is that the result of
CopyPalette is unspecified when your pixel format is not an indexed
color format (in this case, a grayscale format).

So, while it's not really a problem to do that (unless a program
relies on the exact behavior of this decoder, which seems unlikely),
for correctness you shouldn't ever be relying on this change.