Super minimal host based secrets

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)

Conflicts:
	daemon/container.go
only forward auth to trusted locations

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)

Conflicts:
	registry/registry.go
Fix SELinux label on secrets pull