The rule generating the HTML docs passing the --html flag
to xsltproc. This makes it use the legacy HTML parser, which
either ignores or tries to fix all sorts of broken XML tags.
There's no reason why we should be writing broken XML in
the first place, so removing --html and adding the XHTML
doctype to all files forces us to create good XML.

This adds the XHTML doc type and fixes many, many XML tag
problems it exposes.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This enrichs HBA's xml by dumping the number of max vports and
vports in use. Format is like:

  <capability type='vport_ops'>
    <max_vports>164</max_vports>
    <vports>5</vports>
  </capability>

* docs/formatnode.html.in: (Document the new XML)
* docs/schemas/nodedev.rng: (Add the schema)
* src/conf/node_device_conf.h: (New member for data.scsi_host)
* src/node_device/node_device_linux_sysfs.c: (Collect the value of
  max_vports and vports)

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.