Update libcontainer to 5210a236b92a8022a673108f347
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Update libcontainer references
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Rename libcontainer.Container to libcontainer.Config
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #6650 from crosbymichael/update-libcontainer-post-refactor

Update libcontainer dep to 5210a236b92a8022a673108f347