* The actual value is only relevant when ioMode != PIO_NONE.

* Because it holds the namespace the unpacked resource comes from.

* This also adds separate documentation, header, Fortran wrappers and
  pkg-config file for the cdi-pio part of the library

* This also fixes a previously introduced memory leak.

* This will enable functions in pio_interface later to be written
  without regard for header specifics.

* This allows to have the offset entry available for all types.

* This ensures a consistent traversal on all I/O tasks.

* This ensures synchronization.