Enhanced QuickSort: Sort array of comparable values with quicksort

This class implements an enhanced version of the quicksort algorithm to sort an array of comparable values.

It uses a cutoff point to switch to an insertion sort when the array size has become too small for quicksort to be useful. It is recommended for use with arrays of 10,000 items or less.

It can sort comparable values of type integer, double or strings which convert to integers.