Move Partition() object creation into the actual Partition object,
rather than having the logic within the Partitioning() object
Change-Id: I833ed419a0fca38181a9e2db28e5af87500d8ba4
Split Partition() into it's own file for clarity. This will be
followed-on by less dependence between Partitions and Partition
Change-Id: I860f6a1787c0e4fe99f93919ac37cf7d80bfaae9