to indicate that they only work for atomic types,
not user defined types.
2. modified NCDEFAULT_{get/put}_vars to no longer use
nc_get/put_varm. They now directly use nc_get/put_vara
directly. This means that nc_get/put_vars now work
properly for user defined types as well as atomic types.
3. Added test cases for get_vars/put_vars with a
user defined type. Tests placed into
nc_test/tst_compounds.c
contain as little file-type specific info as possible. It
modifies especially libsrc so that all of the netcdf-3 data
that used to be in struct NC is now kept in a separate chunk
of data pointed to by the struct NC. This makes all of
current protocols consistent: netcdf-3, netcdf-4, and dap.
