Fixed a problem in the backing up of symlinks and devices: we

Fixed a problem in the backing up of symlinks and devices:  we
need to remove any old symlink/device/file to create the backup.
Also fixed a couple minor logic errors in the handling of symlinks
and devices.  NOTE:  the code still doesn't handle the changing of
a name from a dir to a non-dir or visa versa (which is a very old
deficiency in the code).