* 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).

[cdi-tiles] changed locking mechanism st. the original vlist of a stream is locked as soon as it is attached to the stream.

[cdi-tiles] implemented auxiliary routine which simply checks if resource handle exists (without error message).