Put the power modes in a list to make them easier to find.

Reviewed by:	joel
MFC after:	1 week
Fix dhclient for interfaces that are down. The discover_interfaces() function
that looks for interface skips interfaces that are not UP. We need to call
dhclient-script PREINIT before we call discover_interfaces(), so the script has
a chance to bring the interface UP.

Reported by:	alfred
Style fix noted by bde@