...it had been deprecated at least since late OOo times, with the
css.sheet.NamedRangeFlag constant group as replacement.  (UNOIDL identifiers
starting with an underscore are illegal.  It would be good to be able to enforce
that in code parsing UNOIDL files, but some existing identifiers like this one
violate that.)

Change-Id: Ib8067dee47cec46356065b7b70cc6b47b97e5bc0