Comment 5 for bug 922645

Actually the extra changes weren't as crucial as I'd thought, but the one part was badly behaving when config was not yet written (as it might not if lxc-ubuntu exits early), so it's nice to have.

The new version (correctly) exits with 1 and cleans up when i mess up networking for the container so that it can't install lxcguest. Pushed to oneiric-proposed.