Statistics.Sample.KernelDensity.Simple is deprecated?

Hi,

I wanted to learn more about this module's deprecation. I want to specify the lower and upper bounds for an estimate, where the lower and upper bounds extend beyond the range of the sample data. I was unable to get the results I want with `Statistics.Sample.KernelDensity.kde_`, but found that `Statistics.Sample.KernelDensity.Simple.estimatePDF` works perfectly. My question is, should `kde_` be able to do everything that `estimatePDF` can? Is there something I need to do to the data I pass into `kde_`? Here's an example:

With the following test data:

```haskell
let demoData = V.fromList $ concat $ zipWith replicate [5, 4, 3, 7] [0..3]
```

The following estimate:

```haskell
-- xValues has 'n' values ranging from 'a' to 'b'.
Stats.estimatePDF Stats.gaussianKernel bw demoData (Points xs)
```

Returns an estimate like this:


While the following code:

```haskell
Stats.kde_ n a b demoData
```

Returns an estimate like this:


Thanks