[1.3.X] Fixed #16595 - Add pop() to session docs; thanks wilfred.

Backport of r16628 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.3.X@16629 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/topics/http/sessions.txt

@@ -132,6 +132,10 @@ You can edit it multiple times.
 
       Example: ``fav_color = request.session.get('fav_color', 'red')``
 
+    .. method:: pop(key)
+
+      Example: ``fav_color = request.session.pop('fav_color')``
+
     .. method:: keys
 
     .. method:: items