Invokes Zoltan library and requires MPI. Client code constructs an
abstract connectivity graph by defining connections/edges through
the 'registerConnection()' member function. May also impose a
restriction that certain cells/vertices be placed in the same
domain/block in the resulting partition. Client code must supply a
callback function that defines globally unique cell/vertex/object
IDs, across all MPI ranks, for each vertex in the connectivity
graph.
Member function 'partitionElement()' forms the resulting partition
vector, the size of which is the total number of objects visible to
the local rank-typically the number of cells owned by the rank, and
the number of overlap cells--i.e., the size of the local grid view.
