* This partially reverts "added support for C89/90 preprocessor" which only
  covered up an already bad situation.

Using the C preprocessor on Fortran sources does ultimately not work
since it doesn't know about Fortran-specific features like the _OPENMP
macro and is chronically likely to pick up the cpp belonging to
another compiler (e.g. to system gcc when compiling with xlf on Linux/ppc).

* It's only in grib_api releases 1.12 and after.

* Also automatically find cfortran.h flag for as many platforms as we
  can test at the moment.

* This way the MPI parts of CDI can be compiled without introducing
  an artificial MPI dependency for non-MPI parts.

* This test currently only checks if a single missing value is
  successfully written out and counted on input.

* This partially reverts "added support for C89/90 preprocessor" which only
  covered up an already bad situation.

Using the C preprocessor on Fortran sources does ultimately not work
since it doesn't know about Fortran-specific features like the _OPENMP
macro and is chronically likely to pick up the cpp belonging to
another compiler (e.g. to system gcc when compiling with xlf on Linux/ppc).