ganglia GraphView integration

Ganglia implementation for http://tumblr.github.com/collins/configuration.html#graphs

Note: This relies on ad-hoc-views which recently
![ganglia-collins-demo](https://f.cloud.github.com/assets/24433/263278/093d23ce-8d65-11e2-8b2d-3eb38a923522.png)
 landed in ganglia-web master https://github.com/ganglia/ganglia-web/pull/159