Handle symlinks to directories in LispWorks

[tfeb]

If a symlink points to a directory, then LW will, if link transparency is false (which it is) return its name as a filename from directory: as a name whose file-namestring is not nil in other words. Deal with this in directory-entries by appending the name to the directory components.

This should deal with issue #226.

I think this is a better fix than PR #222 which currently has problems with packages.