In addition to config env, `commit` now will also accepts a `changes` env which
is a string contains new-line separated Dockerfile instructions.
`commit` will evaluate `changes` into `runconfig.Config` and merge it with
`config` env, and then finally commit a new image with the changed config
Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: dqminh)
Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: rhatdan)
Upstream-commit: b30257ccf96f646c6b008312d39544d6700f5cb1
Component: engine