Add more label checks for selinux enabled
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Ensure that selinux is disabled by default

This also includes some portability changes so that the package can be
imported with the top level runtime.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)