field::refinement::PackInfo should permit specifying number of ghost layers to communicate
For uniform grids,
field::communication::PackInfo's constructor has an optional argument
numberOfGhostLayers that specifies how many ghost layers should be exchanged. If it is not given, then all ghost layers are exchanged.
For refined grids,
field::refinement::PackInfo, having otherwise identical functionality to its non-refined counterpart, does not permit specifying the number of ghost layers to exchange. In fact, it does not even exchange all ghost layers, but only communicates one layer of the coarse field to two layers of the fine field. Functionality to specify the number of ghost layers should be added. For consistency with non-refined simulations, the number of ghost layers should be specified from the perspective of the coarse field, so if
2 is given, 2 ghost layers of the coarse grid should exchange data with 4 ghost layers of the fine grid.