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.
@rjnagal is right. []int8 cannot directly convert to []byte, you have to manually change it.