NetworkManager dependency

[Ethan Blanton]

Michael McConville spake unto us the following wisdom:
> I think we all agree that the configuration should be explicit. It seems
> like the discussion is just whether or not NM should be on by default.
> What are your thoughts on that? I think it should probably be off by
> default because it's only used for a minor supporting feature and it's
> usually only available on one platform.

That platform is, of course, like 99.5% of our installed base for
platforms that use autoconf.

Ethan