libvirt.tests: Add testcases for migration with copy-storage-inc/all.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
libvirt.tests: Add testcases for lvm type storage migration.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
libvirt.tests: Add abnormal testcases for storage migration.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
tests.migrate_copy_storage: Fix bugs.

 * LVM should be block device for domain.
 * New created vm should be cleaned up anyway.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
Merge pull request #103 from yumingfei/storage_migration

libvirt.tests: Add testcases for migration with copy-storage-inc/all.