Remove the id-based optimization in the repos verification code
and replace it with a fast noderev validity check.

This is still much faster than reading whole sub-directories and
it also doesn't require additional I/O in FSFS since all noderevs
have already been accessed.

* dump.c
  (edit_baton): Remove cache member.
  (get_dump_editor): Remove cache pass-through parameter.
  (svn_repos_dump_fs3): Update caller.
  (verify_directory_entry): Simplify node validity check and drop
                            cache-based code.
  (verify_one_revision): Remove cache pass-through parameter.
  (serialize_node_kind,
   deserialize_node_kind): Drop now obsolete functions.
  (svn_repos_verify_fs3): Don't create the cache anymore.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1553053 13f79535-47bb-0310-9956-ffa450edef68