Report MediaWiki wfDebug() log counts to Ganglia via Gmetric

- udp2log on fluorine: forward everything to localhost:8324
- configure 'wfdebug-ganglia' upstart service
- service runs wfdebug-ganglia.py, which keeps count and flushes to ganglia
  using gmetric.
- gets rid of centralauth_log_processor

Change-Id: Ibf3bb07c968673b9d5b291da34a18fd19754cd97