Allow output_type to work as advertised.

According to the readme, specifying an output_type will allow stats
to pass to a configured endpoint by the same name. However, this
next statement prevented anything except graphite or opentsdb
output_types from ever being queued and eventually posted.

This change fixes this behavior so it works as documented.
Adding ability to parse nagios perfdata if the check is defined with
"output_type: nagios".
Fixing graphite naming scheme to match what is already happening for sensu
metrics.
Merge branch 'support_output_type' of github.com:csmcdermott/sensu-metrics-relay
Updating graphite storage path to match what we're using in prod right
now