Directory symlinks are not matched by wildcards in Groups

For example, the following Group:

Group {
    files: [
        "/Library/Frameworks/*.framework/**"
    ]
}

will not include "/Library/Frameworks/Cocoa.framework/Versions/Current", which is a directory symlink, unless said patch is explicitly listed in the Group. This complicates installation of Apple frameworks, for example.

Perhaps we should introduce a new property to prevent Group wildcards from following directory symlinks when gathering their artifact lists?