o  remove copy_dir code, or use it
o  handle large object comments;  this is difficult to do because the large object
   doesn't exist when --schema-only is loaded
o  consider using pg_depend for checking object usage in version.c
o  if reindex is necessary, allow it to be done in parallel with pg_dump custom format
o  migrate pg_statistic by dumping it out as a flat file, so analyze is not necessary