Unconditionally apply HANDLE_NOTIFY_FROM_MERGE in the merge code.

No functional changes.

* subversion/libsvn_client/merge.c
  (merge_cmd_baton_t,
   record_skip,
   record_tree_conflict,
   record_update_add,
   record_update_update,
   record_update_delete,
   merge_dir_closed,
   record_operative_merge_action): Enable conditional blocks.

  (do_file_merge): Remove old merge support that was disabled.
  (do_merge): Enable conditional block.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1440217 13f79535-47bb-0310-9956-ffa450edef68