CustomImagePull is a client side `smart` Pull, that only pulls if the digests are not matching.

Exists checks local references using a filter, this uses exact matching.

force pulls the given image name TODO(@nandor-magyar): the output from docker is not really nice, should be improved.

errors.

errors.

InProgressMessages status strings.

PullResponse is not explicit.

RegistryAuth defines an image registry and the authentication information associated with it.