Return a better error message when a target of 'cp --parents' exists, but is a file.
Return a better error message when a target of 'cp --parents' exists, but is
a file.

* subversion/libsvn_client/copy.c
  (repos_to_repos_copy, wc_to_repos_copy): Toss an error if we reach and
    existent "to-be-created" parent directory, but isn't not a directory.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion