If the netCDF-C library is built with the
HDF5 library but without the HDF4 library and one attempts
to open an HDF4 file, an abort occurs rather than returning
a proper error code (NC_ENOTNC).
Fix is to modify dfile.c#NC_check_file_type to properly
#ifdef relevant tests.
The code for handling character constants
in datalists in ncgen has some problems.
1. It failed on large constants
2. It did not handle e.g. var = 'a', 'b', ...
in the same way that ncgen3 did.
3. The code for generate.c and genchar.c needed
some refactoring to make it a little simpler
(but not simple).
times, but returning the same ncid.
2. Separate out the dap auth tests
and make them disabled by default.
3. turn of ncdap_test/test_varm3 until
we can find a copy of coads_climatology.nc
