Slicey

Pie Chart Library
Mmmmh. You are using `getValues` only here, and to create an array that you use only for counting.
At this point I'd kill both `getValues` and `sum` and write:
```
    scope.total = 0
    for datum in scope.dataset then scope.total += datum.value
    scope.arcs = @getArcs scope.dataset, scope.total
```