add support extra_cdrom_ks installation for WinNT6.0 guest

Signed-off-by: Xu Tian <xutian@redhat.com>
update ks to execute finish.bat from root partition

Signed-off-by: Xu Tian <xutian@redhat.com>
fix extra_cdrom_ks installation params

Signed-off-by: Xu Tian <xutian@redhat.com>
Merge pull request #1495 from xutian/extra_cdrom_ks_installation

Add support extra_cdrom_ks installation test for WinNT6.0 guest