While it is undesirable for the system or user git config to be used
when the daemon clones a Git repo, it could break workflows if it was
unconditionally applied to docker/cli as well.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Redefine a better interface for remote context dependency.
Separate Dockerfile build instruction from remote context.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>