fence_netio: new fence-agent for the Koukaam NETIO-230B PDU

The Koukaam NETIO-230B is a power distribution unit with four normal
(European) sockets. The device has a webui and a telnet interface. Each
socket can be given a custom name, which is returned with '-o list'.

Link to the device, its specifications and API:

• http://www.koukaam.se/kkm/showproduct.php?article_id=1502

Signed-off-by: Niels de Vos <ndevos@redhat.com>