This patch is to expose the fabric_name of fc_host class, which
might be useful for users who wants to known which fabric the
(v)HBA connects to.
The patch also adds the missed capabilities' XML schema of scsi_host,
(of course, with fabric_wwn added), and update the documents
(docs/formatnode.html.in)
Coupled with the recent virsh nodedev-* doc patch, this should now
give a better picture of libvirt node device handling.
* docs/formatnode.html.in: Fill in page.