The previous code resulted in the following error when compiled with
GCC 6.4.0 and FCFLAGS=-std=-f2008:

TS 29113/TS 18508: Noninteroperable array FPTR at (1) to C_F_POINTER: Type shall have a character length of 1

Moreover, the code did not really reflect how the string manipulation
was implemented in src/mo_cdi.f90. The updated version is supposed to
be closer to what is required in the real code.

Fail the configure script when Fortran 2003 interface is requested but the compiler does not support CHARACTER interoperability.

Give the compiler a chance to clean its temporary files when requesting its version at the configure time.

* collSpec is meant to be a dumb data collection, none of its member should
  be subject to change.

* gcc 6.4 does not realize posix_memalign initializes ptr on some
  Linux systems.

* The previous implementation had the destructor also release the mapping.

* That was problematic, because the internals of objects depended on
  the external mapping unnecessarily.

* This also fixes a potential double-free issue discovered by Jan
  Frederik Engels.

* Not yet created resource handles are by definition unused.

* This applies to NetCDF where the first write contains invariants that
  are not present in later writes.

* Especially create the latitudes symmetrically from pole to pole.