Setup Nut UPS monitoring on OpenBSD

Seems to be some problem connecting Eaton Powerware 5110 to OpenBSD 4.6. See Eaton PW5110 + nut-2.4.1 + OpenBSD. nut have added some support in version 2.4.2 (See 2.4 ChangeLog but that is not yet ported to OpenBSD.

The tool complains about usb_clear_halt() missing in libusb. Dont know if/when this will be supported in OpenBSD.

pollonly options may also work.

nut is updated to nut 2.4.3 in OpenBSD 4.7.