Give the directors another method which returns not the backend to

Give the directors another method which returns not the backend to
connect to, but a connection to a backend, this makes it possible
for the directors to choose another backend, if connection to the
first backend fails.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3120 d4fa192b-c00b-0410-8231-f00ffab90ce4