add cross reference to mimetools module

Doc/lib/librfc822.tex

@@ -93,6 +93,8 @@ switch dates.  Not enough to worry about for common use.
 \begin{seealso}
   \seemodule{mailbox}{Classes to read various mailbox formats produced 
                       by end-user mail programs.}
+  \seemodule{mimetools}{Subclass of rfc.Message that handles MIME encoded
+		        messages.} 
 \end{seealso}