This simple script uses varnishncsa tool to provide a way to store varnish logs
with vhost, cause varnish by default until version 2.1.5 not allow to customize
log formats.

The output produced by this wrapper is the as 'combined' from Apache LogFormat
plus virtualhost. See apache config below as example used by me.

LogFormat "%v %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined