Get root container stats from cAdvisor

I changed the GetContainerStats function, which will return the root container's stats if the container name is empty. This is useful when the master wants to know machine wide information. e.g. total memory usage of a certain node.
I take it this path is different than the stats/pod/container path? Can you document what this path is? Also, perhaps the name "statsFromContainerPath" is more concise.