Adding a basic oob helper as an example

This is just a plain stupid and simple out-of-band helper without
anything fancy. It uses plain ssh to power off / power cycle the
machine, does not support power on. It support power status using fping
to check if the host replies.

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>