The DNS director allows Varnish to pick backend based on the Host header
provided by the client, and how it resolves in DNS. A suffix can be added
to make it "internal" (see vcl(7)).

There's still some quirks that I want to work out, but this seems fairly
commit-ready and non-intrusive.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5062 d4fa192b-c00b-0410-8231-f00ffab90ce4