Add version information for components we depend on.

Sample output:
Version: {KernelVersion:3.11.0-17-generic ContainerOsVersion:Ubuntu 14.04 LTS DockerVersion:1.0.0}

This is the start of the debug page. Still need to add cgroup and namespaces status plus the final debug page.
I'm not familiar with that one, it seems like the index is there just for this purpose. But I'm fine either way. @monnand if he knows offhand.