The Mac OS X "installers" are just ".dmg" files with a particular
layout and background image, which are record in a ".DS_Store" file
in the disk image. We have been generating a ".DS_Store" file through
an AppleScript program and Finder, but that script has been fragile,
and the result depends on the version of Mac OS used to generate
the image (e.g., an imagine generated on 10.7 does not look right
on 10.5).
A new `ds-store' library can write ".DS_Store" files directly,
and it uses a format that is compatible with old Mac OS X versions.
original commit: b3390a7e2a89a1c54abc20d61571435bf7f9cf7b
ae4a03038e