[radvd-devel-l] [BUG Report]Prefix announce when AdvPreferredLifetime equals 0.

[Li Wei]

Hi, all.

I'm using radvd-1.8.1 on my fedora box and noticed that when 
AdvPreferredLifetime set to zero, the Prefix option will missing
in the RA packet.

I also noticed a "DecrementLifetimes" config option was added, but
when this option set to off, I expected radvd sends RA packets with
a prefix option(PreferredLifetime equals zero).

Thanks,
Wei