They are attached to the cells as well and are now distributed
during CpGrid::loadBalance. Due to this change we also rename
FieldPropsDataHandle to PropsCentroidsDataHandle.
The created data handle for the communication could in theory be used
with other DUNE grids, too. In reality we will need to merge with the
handle that ALUGrid already uses to communicate the cartesian indices.
This PR gets rid of using the get_global_(double|int) method in
ParallelEclipseState and reduces the amount of boilerplate code there.
these are wrappers sitting on top of the EclipseState and
FieldPropsManager classes.
The former has some additional methods related to parallelism,
and the latter is a parallel frontend to the FieldPropManager which
only hold the process-local data (in compressed arrays).
