[NCF-287/MCI-552767
Problem related to NCF-284.
Namely an old thredds server that
does not properly implement the
dap2 spec. It is accessing a field of a grid
but is not wrapping it as a structure.
url:http://thredds.aodn.org.au/thredds/dodsC/IMOS/ACORN/gridded_1h-avg-current-map_QC/SAG/2010/01/27/IMOS_ACORN_V_20100127T023000Z_SAG_FV01_1-hour-avg.nc.dds?SPEED.SPEED

In any case, this exposed another bug.
Also, in looking at this, I realized that the
code could be simplified.
Merge branch 'master' of http://github.com/Unidata/netcdf-c