sort and partsort arguments

[dbv]

For an array of length m, bottleneck.partsort(arr, n) returns the n smallest elements at the beginning of the array which can be captured with bottleneck.partsort(arr, n)[:n]

The largest n elements are returned at the end of the array with bottleneck.partsort(arr, m-n), which can be captured with bottleneck.partsort(arr, m-n)[-n:]

If so, would it be easier to support:

bottleneck.partsort(arr, n) and bottleneck.partsort(arr, n)[:n] to return the smallest n elements

and

bottleneck.partsort(arr, -n) and bottleneck.partsort(arr, n)[n:] to return the largest n elements