Add support for XEP-0118.

See examples/user_tune.py for a demonstration using the currently
playing song in iTunes.

sleekxmpp/plugins/xep_0118/stanza.py

@@ -0,0 +1,25 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2012 Nathanael C. Fritz, Lance J.T. Stout
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+from sleekxmpp.xmlstream import ElementBase, ET
+
+
+class UserTune(ElementBase):
+
+    name = 'tune'
+    namespace = 'http://jabber.org/protocol/tune'
+    plugin_attrib = 'tune'
+    interfaces = set(['artist', 'length', 'rating', 'source', 
+                      'title', 'track', 'uri'])
+    sub_interfaces = interfaces
+
+    def set_length(self, value):
+        self._set_sub_text('length', str(value))
+
+    def set_rating(self, value):
+        self._set_sub_text('rating', str(value))