LOGSTASH-978 - an input for the varnish shared memory binary log
now that varnish-rb is on rubygems we dont need to include the 4rd party code anymore.
andrea, author of varnish-rb, says the callback should return 0, so now it does
Merge pull request #422 from semiosis/LOGSTASH-978

LOGSTASH-978 - an input for the varnish shared memory binary log