Document the quoting of cookie values.

lib/python/Products/OFSP/help/Response.py

@@ -120,6 +120,11 @@ class Response:
         "value". This overwrites any previously set value for the
         cookie in the Response object.
 
+        The value passed in is quoted using url_quote_plus before
+        the cookie is sent to the browser, and is unquoted using
+        url_unquote_plus when the cookie is received back from
+        the browser and stored in REQUEST.cookies.
+
         Permission -- Always available
         
         '''