virsh.undefine: adapt undefine to lxc test.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
virsh.dumpxml: adapt virsh.dumpxml to lxc test.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
virsh.edit: adapt virsh.edit to lxc test.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
virsh.start: adjust virsh.start to lxc.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Merge pull request #221 from yangdongsheng/lxc

lxc: adapt virsh tests to lxc test.