[1.7.x] Specified 'csv and unicode' note as Python 2 only

Backport of 2128b3a6 from master.

docs/howto/outputting-csv.txt

@@ -54,26 +54,25 @@ mention:
   about escaping strings with quotes or commas in them. Just pass
   ``writerow()`` your raw strings, and it'll do the right thing.
 
-Handling Unicode
-~~~~~~~~~~~~~~~~
+.. admonition:: Handling Unicode on Python 2
 
-Python's :mod:`csv` module does not support Unicode input. Since Django uses
-Unicode internally this means strings read from sources such as
-:class:`~django.http.HttpRequest` are potentially problematic. There are a few
-options for handling this:
+    Python 2's :mod:`csv` module does not support Unicode input. Since Django
+    uses Unicode internally this means strings read from sources such as
+    :class:`~django.http.HttpRequest` are potentially problematic. There are a
+    few options for handling this:
 
-* Manually encode all Unicode objects to a compatible encoding.
+    * Manually encode all Unicode objects to a compatible encoding.
 
-* Use the ``UnicodeWriter`` class provided in the `csv module's examples
+    * Use the ``UnicodeWriter`` class provided in the `csv module's examples
       section`_.
 
-* Use the `python-unicodecsv module`_, which aims to be a drop-in
+    * Use the `python-unicodecsv module`_, which aims to be a drop-in
       replacement for :mod:`csv` that gracefully handles Unicode.
 
-For more information, see the Python documentation of the :mod:`csv` module.
+    For more information, see the Python documentation of the :mod:`csv` module.
 
-.. _`csv module's examples section`: http://docs.python.org/library/csv.html#examples
-.. _`python-unicodecsv module`: https://github.com/jdunck/python-unicodecsv
+    .. _`csv module's examples section`: http://docs.python.org/2/library/csv.html#examples
+    .. _`python-unicodecsv module`: https://github.com/jdunck/python-unicodecsv
 
 .. _streaming-csv-files: