more complicated than a single file can carry.

cache_backend_cfg.c now contains the configuration and selection of
backends and directors.

cache_backend.c contains the connection and request management against
backends.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@2905 d4fa192b-c00b-0410-8231-f00ffab90ce4