Files api

That's true. So I guess we need to either:
 - Only support pulling/pushing to running containers
 - Have two different code paths, one for the running containers and one for the stopped containers

The reason being that "lxc pull blah /run/some-file ." should work and as /run is a tmpfs in the container, the only way this will ever work is if you pull through /proc rather than accessing the rootfs directly.