Updated the XEP-0085 plugin.

Can now be used as so:

>>> msg['chat_state']
''
>>> msg
<message />

>>> msg['chat_state'] = 'paused'
>>> msg
<message>
  <paused xmlns="http://jabber.org/protocol/chatstates" />
</message>

>>> msg['chat_state']
'paused'

>>> del msg['chat_state']
>>> msg
<message />

sleekxmpp/plugins/xep_0085/chat_states.py

@@ -0,0 +1,48 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2011 Nathanael C. Fritz, Lance J.T. Stout
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permissio
+"""
+
+import logging
+
+import sleekxmpp
+from sleekxmpp.stanza import Message
+from sleekxmpp.xmlstream.handler import Callback
+from sleekxmpp.xmlstream.matcher import StanzaPath
+from sleekxmpp.xmlstream import register_stanza_plugin, ElementBase, ET
+from sleekxmpp.plugins.base import base_plugin
+from sleekxmpp.plugins.xep_0085 import stanza
+
+
+log = logging.getLogger(__name__)
+
+
+class xep_0085(base_plugin):
+
+    """
+    XEP-0085 Chat State Notifications
+    """
+
+    def plugin_init(self):
+        self.xep = '0085'
+        self.description = 'Chat State Notifications'
+        self.stanza = stanza
+
+        self.xmpp.registerHandler(
+            Callback('Chat States',
+                     StanzaPath('message/chat_state'),
+                     self._handle_chat_state))
+
+        register_stanza_plugin(Message, stanza.ChatState)
+
+    def post_init(self):
+        base_plugin.post_init(self)
+        self.xmpp.plugin['xep_0030'].add_feature(stanza.ChatState.namepsace)
+
+    def _handle_chat_state(self, msg):
+        state = msg['chat_state']
+        log.debug("Chat State: %s, %s" % (state, msg['from'].jid))
+        self.xmpp.event('chatstate_%s' % state, msg)