Refactor merge_dir_props_changed() and merge_dir_added() to become propert
diff tree processor functions. This temporarily duplicates some code that
was used for quite different purposes.

* subversion/libsvn_client/merge.c
  (merge_dir_props_changed): Rename this function to ...
  (merge_dir_changed): ... this. Extract the new directory code into ...
  (merge_dir_added): ... this function.

  (ignore_dir_props_changed,
   ignore_dir_added): New stubs.
  (merge_callbacks): Install stubs.

  (do_merge): Hook property change functions.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1440575 13f79535-47bb-0310-9956-ffa450edef68