[1.3.X] Fixed #16886 -- Memcached socket file documentation. Thanks ddbeck for the report and patch.

Backport of [16858] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.3.X@16859 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/topics/cache.txt

@@ -99,8 +99,9 @@ To use Memcached with Django:
       on your chosen memcached binding)
 
     * Set :setting:`LOCATION <CACHES-LOCATION>` to ``ip:port`` values,
-      where ``ip`` is the IP address of the Memcached daemon and
-      ``port`` is the port on which Memcached is running.
+      where ``ip`` is the IP address of the Memcached daemon and ``port`` is the
+      port on which Memcached is running, or to a ``unix:path`` value, where
+      ``path`` is the path to a Memcached Unix socket file.
 
 In this example, Memcached is running on localhost (127.0.0.1) port 11211, using
 the ``python-memcached`` binding::
@@ -112,6 +113,16 @@ the ``python-memcached`` binding::
         }
     }
 
+In this example, Memcached is available through a local Unix socket file
+:file:`/tmp/memcached.sock` using the ``python-memcached`` binding::
+
+    CACHES = {
+        'default': {
+            'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
+            'LOCATION': 'unix:/tmp/memcached.sock',
+        }
+    }
+
 One excellent feature of Memcached is its ability to share cache over multiple
 servers. This means you can run Memcached daemons on multiple machines, and the
 program will treat the group of machines as a *single* cache, without the need