Fixed #20852 - Fixed incorrectly generated left quotes in docs.

Sphinx generates left single quotes for apostrophes after
code markup, when right single quotes are required. The
easiest way to fix this is just by inserting the unicode
character for a right single quote.

Instances of the problem were found by looking for
">‘" in the generated HTML.

docs/ref/contrib/admin/index.txt

@@ -1615,7 +1615,7 @@ in your own admin JavaScript without including a second copy, you can use the
     The embedded jQuery has been upgraded from 1.4.2 to 1.9.1.
 
 The :class:`ModelAdmin` class requires jQuery by default, so there is no need
-to add jQuery to your ``ModelAdmin``'s list of media resources unless you have
+to add jQuery to your ``ModelAdmin``’s list of media resources unless you have
 a specifc need. For example, if you require the jQuery library to be in the
 global namespace (for example when using third-party jQuery plugins) or if you
 need a newer version of jQuery, you will have to include your own copy.

docs/ref/contrib/auth.txt

@@ -243,7 +243,7 @@ Manager methods
         be called.
 
         The ``extra_fields`` keyword arguments are passed through to the
-        :class:`~django.contrib.auth.models.User`'s ``__init__`` method to
+        :class:`~django.contrib.auth.models.User`’s ``__init__`` method to
         allow setting arbitrary fields on a :ref:`custom User model
         <auth-custom-user>`.
 

docs/ref/contrib/comments/moderation.txt

@@ -54,7 +54,7 @@ following model, which would represent entries in a Weblog::
 Now, suppose that we want the following steps to be applied whenever a
 new comment is posted on an ``Entry``:
 
-1. If the ``Entry``'s ``enable_comments`` field is ``False``, the
+1. If the ``Entry``’s ``enable_comments`` field is ``False``, the
    comment will simply be disallowed (i.e., immediately deleted).
 
 2. If the ``enable_comments`` field is ``True``, the comment will be