Changed metrics from zag to influxdb

 Switched clients from zag to my more generic emitter. Updated the dev config so the emitter now sends to the new collector host. The emitter does a little bit of metric name rewriting, but I have not touched all the invocations. The new metrics system allows for a lot more flexibility in what you emit.

Tested on dev & staging. See the matching PR for deployment, because this requires some config variation from staging to prod.