This adds support for the passthrough on build, push, login, and search. Revamp the integration test to cover these cases and make it more robust. Use backticks instead of quoted strings for backslash-heavy string contstands. Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com> Upstream-commit: c44e7a3e632c3ea961cb8c12ba45371f54e6699c Component: engine