removed const since c++ does not allow to use memcpy with a const lvalue destination, removed array length in array parameters brackets, changed type of len from size_t to int since it is only used as int and replaced anonym funtion that cast len to int by &len

added explicit cast in line 267, changed parameter uuid[CDI_UUID_SIZE] to *uuid in function cdiUUIDIsNull

* Original patch by Nathanael Hübbe.

* 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).

* The only user immediately destroyd the copy.

* Replace expensive function call with comparison.

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