CFT: IPv6 DNS autoconfiguration (RFC6106 RDNSS and DNSSL)

[J.R. Oldroyd]

I have updated the rtadvd patch to allow greater flexibility in configuring
DNS servers and search domains in rtadvd.conf.

The new patch allows comma-separated values in the "rdnss=" and "dnssl="
entries and now sends separate RA RDNSS and DNSSL options for each such
entry.  This allows separate lifetimes to be given for each RA option.

Previously,
	:rdnss="2001:db8:ffff::1":rdnss0="2001:db8:ffff::2":\
	:rdnssltime#1200:
sent one RA RDNSS option containing two server IPs with the one lifetime.

Instead, you can now say:
	:rdnss="2001:db8:ffff::1,2001:db8:ffff::2":rdnssltime#1200:\
	:rdnss0="2001:db8:ffff::3,2001:db8:ffff::4":rdnssltime0#900:
which will send two RA RDNSS options, each with two server IPs and each
with the corresponding lifetime.

Same goes for "dnssl=".

I now also send RA RDNSS and DNSSL options with zero lifetimes when the
server is shut down using a TERM signal.

If you've tried this out and wish to grab this latest version, all you
need is the rtadvd-rdnss.diff update from the web site.  The other three
diffs do not change.

    http://opal.com/jr/freebsd/rdnss/

	-jr