Pi based temperature netsender.

We would like to have the option of collecting temperature data at the location of our cameras using the same pi as the camera. This would mean that for sites like jetty rigs we could monitor water temperature without running an extra cable down the pylons etc.

I think it would be good to keep the software separate to rv from the av repo. It would be good if we can run both rv and a temp-netsender at the same time on the same pi.