Lots of things!

Adds or changes...

* Can specify an arbitrary number of graphs, will figure out how to arrange them. Will even work around prime numbers of graphs (in theory, and in purely numeric tests).
* Adds `stacked` and a related `alpha` option (no UI) to Graphs, which let you add stacked graphs (`areaMode=stacked`) and then adjust their opacity (`areaAlpha=...`). It's useful for stuff like memory use graphs and other server health metrics.
* Moves `js/app.config.js` to `js/app.config.js.example` so it's possible to use this repo without changing important code. Mostly.
* At some point, I changed the storage key so two instances can use the same config file.
* Pick which site you're using with the URL fragment.