Added version indicator to docs for m2m inline change introduced in r11712.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11722 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/contrib/admin/index.txt

@@ -1051,6 +1051,8 @@ automatically::
 Working with Many-to-Many Models
 --------------------------------
 
+.. versionadded:: 1.2
+
 By default, admin widgets for many-to-many relations will be displayed
 on whichever model contains the actual reference to the ``ManyToManyField``.
 Depending on your ``ModelAdmin`` definition, each many-to-many field in your