Label content created for containers with the private label

Currently this content gets a system label and is not writable based on
SELinux controls.  This patch will set the labels to the correct label.

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: jfrazelle)
Label standard mounts within loop

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

Docker-DCO-1.1-Signed-off-by: Michael Crosby <crosbymichael@gmail.com> (github: jfrazelle)
Bump version to v1.4.0

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)