Just creates PartitionVector class and includes it in partition.h so
that it is built and validated by the compiler. Not used anywhere yet.
Implementation strategy is to create a PartitionLUKS class derived from
the Partition class. This implies polymorphism of Partition objects,
which in C++ requires using pointers and references to objects, and not
using objects directly. (See C++ object slicing). Later this
PartitionVector class will be modified to use pointers to Partition
objects and act as the owner of the pointed to Partition objects.
Bug 759726 - Implement Partition object polymorphism
Mike Fleetwood