Add minimal comments to fixManifestLayers
Add minimal comments to fixManifestLayers

This does not really go into why duplicate layers can happen or why it
is worth supporting that; the code originates from
https://github.com/docker/docker/commit/504e67b867865a2835e8002c01087a2cfd7bfd0e ,
which does not explain either.

mikebrow/skopeo,mtrmac/skopeo,projectatomic/skopeo,containers/image,mtrmac/skopeo,mtrmac/skopeo,jwhonce/skopeo,masters-of-cats/image,containers/image,projectatomic/skopeo,jwhonce/skopeo,mikebrow/skopeo