Additions/modifications to quicksort/ and SortingClient
	-> Added Dijkstra's 3-way partitioning implementation of
	   Quick Sort @ quicksort/QuickSort3Way.java.
	-> Renamed the previous Quick Sort implementation to
	   "QuickSort1Way.java".
	-> Added "sort.configure" to define various runtime settings.
	-> Added a class QuickSort.java which will decide which
	   Quick Sort implementation to run via sort.configure.
	-> Added QuickSortParent.java to act as a super class to
	   the different Quick Sort implementations.
	-> SortingClient.java now checks if duplicate values are
	   allowed/desired for the object list via sort.configure.
	-> Some bugfixes to SortingClient.java