only for symlinks that point outside the source tree.  Suggested by Charles
Hines <chuck_hines@VNET.IBM.COM> in PR#1376.  Also apply the option to any
symbolic links in the source portion of a path when --relative is used,
as suggested by Francis Montagnac <Francis.Montagnac@sophia.inria.fr> on
the rsync mailing list in a message titled "New option: --copy-parent-links".