Cleanup cmake MPI module
The old cmake file
DuneMPI.cmake mixed two independent steps:
add_dune_mpi_flags(). This MR renames this file to
AddMPIFlags.cmake following the naming scheme used for several other find packages.
- Deprecate the old file
- Move the
- Replace the manual extraction of compile flags and include directories by the imported target
- Do not call the global
include_directoriesfor mpi include path.
- Resolve an inconsistency with the MPI flags when used with