Rename disk_number -> disk_size in the tdl.rng.

No functional change; it just makes more sense.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Remove unused clientcert, clientkey, and cacert.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Rationalize the verbosity of the calls to genisoimage.

Especially now that we are printing output along the way,
we want to make sure we have a little bit less output,
and more consistent output between the various OSs.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>