Change sanitize_path() to not use clean_fname() because it removes the

Change sanitize_path() to not use clean_fname() because it removes the
trailing slash.  This caused a problem when using "use chroot" and sources
that contained a trailing slash (which prevents the last filename component
of the source from being included in the destination).  Instead, have
sanitize_path() remove "." components and duplicated slashes ("//") itself.