virt-libvirt: add configuration for virsh suspend

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

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
virt-libvirt: some fixes to virsh suspend test.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>