[svn] Fix retrieval of directories when initial CWD is not `/'.

[svn] Fix retrieval of directories when initial CWD is not `/'.
Published in <sxsitkc709p.fsf@florida.arsdigita.de>.

* url.c (parseurl): Don't strip trailing slash when u->dir is "/"
because that strips the *leading* slash, thus forcing relative
FTP retrieval.
* ftp.c (getftp): Convert initial FTP directory from VMS to UNIX
notation for VMS servers.
(ftp_retrieve_dirs): Do not prepend '/' to f->name when
odir is an empty string.