Fix iconutil build errors: “Iconset contains no image resources.”,
followed by “Failed to generate ICNS.”
The error is produced by iconutil because the AppIcon.iconset contains
only symbolic links to the icon resources which aren’t followed.
Replace the symbolic links with duplicates of the original resources,
as well as conform to the “High Resolution Guidelines for OS X” by
adding additional sizes and dpi.
b76d7026e0
