mostly because I've been failing at getting docker `0.6.2` working with
docker-registry `0.6.0` with regard to login and push. I suspect there
may be some mismatched expectations between `auth.ResolveAuthConfig` and
`registry.ResolveRepositoryName`, but I haven't done enough research or
experimentation to think it's anything more than user error. More tests
are good, no?
Upstream-commit: edde4f55e08c879e5a5fdb74abd6e5cc751e4dbb
Component: engine
fmt.Printf and friends will automatically format using the error
interface (.Error()) preferentially; no need to do err.Error().
Upstream-commit: 1277dca3358874d0701685f7ebb52ce66be1b385
Component: engine
