add help func with-unzip with-unzip-entry

I use dynamic-wind wrap a helper fund for unzip and unzip-entry.

So it can use with-unzip to unzip file and do something and auto deleted temporary files.

It make unzip and unzip-entry easier to use.

example:

 (with-unzip "unzip-me.zip"
              (lambda (tmp_dir)
               (with-input-from-file (build-path tmp_dir "test-zip" "1" "data.dat")
                  (lambda ()
                    (test (read-line) => "chenxiao"))))))

(with-unzip-entry "unzip-me.zip" 
                  (build-path "test-zip" "1" "data.dat")
                  (lambda (tmp_file)
                    (with-input-from-file tmp_file
                      (lambda ()
                        (test (read-line) => "chenxiao")))))