Modified provenance code to allocate the minimal space
needed for _NCProperties attribute in file. Basically
required using malloc in the provenance code and in ncdump.
Otherwise should cause no externally visible effects.
Also removed the ENABLE_FILEINFO from configure.ac since
the provenance code is no longer optional.
This consists of a persistent attribute named
_NCProperties plus two computed attributes
_IsNetcdf4 and _SuperblockVersion.
See the 'Provenance Attributes' section
of docs/attribute_conventions.md for details.
User request to have all orphaned DAP2 attributes kept as netcdf
global attributes. This is primarily a change in the oc code
nplus testcase dataset changes.
Result may be inconsistent with netcdf-Java output.
