Let's reduce memory/cpu usage of the dashboards

These things crash a lot. One suggestion [found](http://toxaq.com/index.php/2012/12/running-shopifys-dashing-on-a-raspberry-pi/) says to just refresh the dashboard every hour or so. I've got this one to refresh once every 30 minutes. Also upped the Bitcoin timer to 10 minutes from 5 (should actually show percent change at a lower resolution, which is mildly interesting). Deleted some sample jobs that aren't being displayed, so don't need to take up clock cycles.