Way forward with BIND 8

[ Please respect followups to -arch, thanks. ]

As most of you are probably already aware, there have been two recent
releases of BIND 8. Version 8.3.5 is the "bugfix, and new minor features"
release on the 8.3.x branch that we've currently got in the tree already.
8.4.0 is (more or less) the "all the bug fixes from 8.3.5, plus support
for IPv6 transport" version.

Because there are over 14k lines of diff between the source for 8.3.5 and
8.4.0, I'm hesitant to import the latter right away. Instead, as the
nominal BIND maintainer, I'm proposing the following plan:

1. Import 8.3.5 into HEAD, and upgrade the bind8 port. At the same time,
create a bind84 port for the 8.4.x branch. The port will include the
PORT_REPLACES_BASE functionality that we already have.

2. At some suitable point in the near future (definitely before the next
4.x release), MFC 8.3.5.

3. At some suitable point in the future, probably after the BIND 8.4.1
release, import 8.4.x into HEAD.

I'm definitely in favor of improving support for IPv6, and BIND 8.4.x is
going to be a big step in this direction. I'm just not sure that we should
be adopting it in the base right away. My personal feeling is that having
it in the ports for the convenience of early adopters is sufficient.
However, my purpose in writing is to poll the community... I'm willing to
be persuaded if folks have strong feelings about adopting 8.4.x in the
base sooner rather than later, speak up now.

FYI, for those wondering why I'm not considering BIND 9 for import, please
see http://people.freebsd.org/~dougb/whybind8.html

Doug