cleaned up the heka_logging module to only include the path instead of
the whole URL when capturing logs

added a stats prefix to all metrics so that graphite shows metrics
under a single namespace

added a CarbonOutput so metrics are properly routed into carbon for
statsd visualisation

added docs for setting up hekad with carbon and graphite
removed WhisperOutput section until the plugin is fixed
Merge pull request #59 from crankycoder/features/better-hekad-config

added docs for setting up routing metrics into graphite