qemu: Add sysprep test

Add sysprep tests for QEMU Windows guests:

1) Log into a guest
2) Clean guest with sysprep tools.
3) Boot guest up again.
4) Check that SID in guest has changed.

Changes from V1:
1. Update some code style issues.
2. Log guest ip address when guest boot up again.

Changes from v2:
Fix a bug for getting restart_timeout

Changes from v3:
Delete unused module and parameter.
Update fail message.

Signed-off-by: Feng Yang <fyang@redhat.com>
cfg.guest-os: Update Windows guests related config for sysprep

Signed-off-by: Feng Yang <fyang@redhat.com>