[18.09 backport] Fix client version not being pinned when set, and some refactoring - #188

[18.09 backport] Fix client version not being pinned when set, and some refactoring#188

andrewhsu merged 4 commits into

docker-archive:18.09docker-archive/engine:18.09from

thaJeztah:18.09_backport_fix_version_overridethaJeztah/docker:18.09_backport_fix_version_overrideCopy head branch name to clipboard