verify-agent: test that agent download-file works

Signed-off-by: Olaf Kirch <okir@suse.de>
schema: fix declaration of Tmpfile.size attribute

Signed-off-by: Olaf Kirch <okir@suse.de>
start-kvm: set the guest's hostname and mac address

Signed-off-by: Olaf Kirch <okir@suse.de>