Simplify a few path calculations in the merge code, by using an exact hash of
added directories in the dry run code, instead of a hash of roots.

* subversion/libsvn_client/merge.c
  (merge_b): Remove dry_run_last_added_dir.
  (dry_run_deleted_p,
   dry_run_added_p): Rename argument to local_abspath.
  (dry_run_added_parent_p): Remove function.
  (perform_obstruction_check): Assume that a dry-run added directory allows
    adding children.
  (store_path): New function.
  (merge_file_added): Rename local variable. Remove dry run obstruction
    handling now handled by perform_obstruction_check. Add note about storing
    paths 'added' during dry merge.
  (cache_last_added_dir): Remove function.
  (merge_dir_added): Remove obstruction handling now performed by
    dry_run_added_parent_p. Use store_path().

  (merge_dir_deleted,
   merge_dir_opened): Use store_path().

  (find_nearest_ancestor): Use a plain strcmp for path equal checks.
  (update_the_list_of_added_subtrees): Use store_path().

  (log_noop_revs): Use a plain strcmp for path equal checks.

  (do_merge): Remove initialization.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1435427 13f79535-47bb-0310-9956-ffa450edef68