Probe via SMAPIv2 where we can

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Add a trivial XML printer for probe results.

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Merge pull request #1590 from jonludlam/probe

Probe via SMAPIv2 where we can