Add 'client/util/client-dmg/' from commit '873e7a3cd614e7b2b7430af343fdd82950596e19'

git-subtree-dir: client/util/client-dmg
git-subtree-mainline: 873e7a3cd614e7b2b7430af343fdd82950596e19
git-subtree-split: 873e7a3cd614e7b2b7430af343fdd82950596e19
experimenting with client-dmg git subtree