On the 'moves-tracking-2' branch: Update discussion of node-id addressing,
and let the local node-id form of address be identical to the path-based form.

* subversion/include/private/svn_editor3.h,
  subversion/libsvn_delta/compat3.c
  Update comments.
  (svn_editor3_nbid_t): Define as a 'txn-path' reference.
  (nbid_str): Track the change.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/move-tracking-2@1615074 13f79535-47bb-0310-9956-ffa450edef68