DifferentGridsGeneral tests need work and documentation. #159
Description
The setup logic in the DifferentGridsGeneral tests needs to be clarified. There were minimal checks that the grid sizes were compatible with the communicator size, and the few I saw were not fatal (MPI will happily blow up, though).
For now (after #158 merges), the tests are skipped. If it's possible to reenable them, we should. I think these will only make sense to add to CTest with the 4-rank version. A single-rank test cannot have different (meaningful, non-overlapping) grids.