Let's reduce memory/cpu usage of the dashboards

These things crash a lot. One suggestion [found]() 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.
Merge pull request #17 from websages/feature/save-r-memory

Let's reduce memory/cpu usage of the dashboards