Instead of implementing a special diff driver for added and removed nodes
on repository diffs, drive the normal diff driver for adds, while using
the diff tree processor wrappers to get the result in the right direction
for deletes.

By default anchor the diff one level above the specified target (after revision
resolving), to allow replacements of the target itself to be reported.

* subversion/libsvn_client/diff.c
  (diff_prepare_repos_repos): Obtain repository root and anchor the diff one
    level higher than the specified target if possible.

  (diff_repos_repos_added_or_deleted_file,
   diff_repos_repos_added_or_deleted_dir,
   diff_repos_repos_added_or_deleted_target): Remove functions.

  (diff_repos_repos): Reverse targets when describing a delete. Use diff
    processor reversing and filtering to produce the same result as before.

  (diff_summarize_repos_repos): Remove usage of the old added and deleted
    code. Similar to diff_repos_repos but handles anchor change itself.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1444228 13f79535-47bb-0310-9956-ffa450edef68