Face centers are computed using the cell corners. With this
implementation the face center seen from a cell may be different from the
face center seen from its neighbour.
Face normals with area lenghts are calculated using the face corners
directly not using a triangulation point in the center of the face.
This gives transmissibility almost equal to eclipse.
this makes creating the grid a bit slower because the
transmissibilities need to be calculated twice: once for the
sequential grid and once for the distributed one. while corresponds to
the way `flow_legacy` does the load balancing and it should allow
better results, this does not seem to be the case for the Norne deck
if ZOLTAN is not available:
After loadbalancing process 3 has 4413 cells.
After loadbalancing process 2 has 12390 cells.
After loadbalancing process 0 has 13629 cells.
After loadbalancing process 1 has 21253 cells.
i.e., process 1 is responsible for almost 5 as many cells as process
3.
