Update libcontainer

We have a requirement in Fedora to build everything from 'our' HEAD.  Which has just resulted in an unsolvable chain of dependencies.  Kubernetes requires new cadvisor (0.6.2) but cadvisor requires older libcontainer. Fedora already has a newer libcontainer, and thus we can't update cadvisor.

This patch attempts to update cadvisor to newer libcontainer. Notice that GetStatsCgroupOnly was removed from libcontainer, so I removed it from cadvisor as well.....