for serial netCDF library usage.

* This exercises the code for which a bug was introduced in r3181 and
  fixed in r3200.

* malloc et al. can return NULL on zero-size allocations.
* this commit also reverts the dubious calling of calloc by xmalloc.

* reshGetVal(ue) will always return non-NULL pointers.

* Eliminate unused fields.

* See r2661.