core: added plugins for PubSub et PEP (first drafts)

- plugin for XEP 0060, 0163 and 0107, based on Wokkel's pubsub
- XEP 0115 plugin has been fixed, so generateHash can be called when features have changed (can be usefull to filter PEP)

src/plugins/plugin_xep_0115.py

@@ -96,17 +96,20 @@ class XEP_0115():
         """modify SatPresenceProtocol to add capabilities data"""
         client=self.host.getClient(profile)
         presenceInst = client.presence
+        c_elt = domish.Element((NS_ENTITY_CAPABILITY,'c'))
+        c_elt['hash']='sha-1'
+        c_elt['node']='http://wiki.goffi.org/wiki/Salut_%C3%A0_Toi'
+        c_elt['ver']=XEP_0115.cap_hash
+        presenceInst._c_elt = c_elt
+        if "_legacy_send" in dir(presenceInst):
+            debug('capabilities already added to presence instance')
+            return
         def hacked_send(self, obj):
             obj.addChild(self._c_elt)
             self._legacy_send(obj)
         new_send = types.MethodType(hacked_send, presenceInst, presenceInst.__class__)
         presenceInst._legacy_send = presenceInst.send
         presenceInst.send = new_send
-        c_elt = domish.Element((NS_ENTITY_CAPABILITY,'c'))
-        c_elt['hash']='sha-1'
-        c_elt['node']='http://wiki.goffi.org/wiki/Salut_%C3%A0_Toi'
-        c_elt['ver']=XEP_0115.cap_hash
-        presenceInst._c_elt = c_elt
 
 
     def generateHash(self, profile_key="@DEFAULT@"):