Pack-scan changes

'facts --list' gathers the facts from the systems and prints them. It doesn't need a candlepin instance, or to be registered.

Since the subman fact 'cpu.cpu_socket(s)' and it's virt facts are the ones that matter for rhsm using systems, I think we should collect them.

Not really sure how they should show up as fields though. Easiest is to just pick out the handful that we know are important now and set them. But that means rho has to know the right ones.

Collecting all of them seems like overkill, but I'd have to try it.
(and the next step after that would be puppet 'facter' or chef 'ohai' facts, but
likely overkill)