S9 LIB  (basename string)          ==>  string
        (basename string string2)  ==>  string

Return the rightmost component of the path name given in STRING.
When STRING2 is given also remove a STRING2 suffix (if any) from
STRING.

(basename "/foo/bar/baz")     ==>  "baz"
(basename "/goo/bar.Z" ".Z")  ==>  "bar"
