work around mostly-minor formatting problems; the encodings.idna

example still doesn't come out quite right: a bug in the formatting
tools

Doc/whatsnew/whatsnew23.tex

@@ -1784,7 +1784,7 @@ command, passing it to the correct thread, and waiting for the
 results.  Other interfaces can't be handled automatically but
 \module{Tkinter} will now raise an exception on such an access so that
 at least you can find out about the problem.  See
-\url{http://mail.python.org/pipermail/python-dev/2002-December/031107.html}
+\url{http://mail.python.org/pipermail/python-dev/2002-December/031107.html} %
 for a more detailed explanation of this change.  (Implemented by
 Martin von L\"owis.)
 
@@ -1829,7 +1829,7 @@ to convert between a Unicode domain name and the ASCII-compatible
 encoding (ACE) of that name.
 
 \begin{alltt}
->>> u"www.Alliancefran\c{c}aise.nu".encode("idna")
+>{}>{}> u"www.Alliancefran\c{c}aise.nu".encode("idna")
 'www.xn--alliancefranaise-npb.nu'
 \end{alltt}