virt-libvirt: modify virsh function for virsh destroy

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
virt-libvirt: add test for virsh destroy

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
virt-libvirt: add configuration for virsh destroy

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
virt-libvirt: Make virsh_destroy remote test SKIP by default

* Also fixed up some spacing

Signed-off-by: Chris Evich <cevich@redhat.com>