Pivot reporting framework

I could be wrong but I made a decision not to add this when doing Qty. See the comment in the companion:

```
  // we don't have a double to scalar to avoid people accidentally using a double like .1
  // and losing precision.
  // if you want to divide by a scalar double then write it out long form.
  implicit def intToScalarQty(value: Int) : BDQty = Qty(BigDecimal(value), SCALAR)
```

Maybe we could add those methods to DblQty and not BDQty? Or maybe I'm just wrong.