core: better handling of profile_key and don't write the param file anymore

- new error ProfileNotSetError and some methods use the default @NONE@ instead of @DEFAULT@
- do not output the .sat/param file anymore, it is not needed and created confusion
- plugin XEP-0054: remove an error message at startup

frontends/src/quick_frontend/quick_chat_list.py

@@ -28,9 +28,9 @@ class QuickChatList(dict):
         dict.__init__(self)
         self.host = host
 
-    def __getitem__(self,to_jid):
-        target=JID(to_jid)
-        if not self.has_key(target.short):
+    def __getitem__(self, to_jid):
+        target = JID(to_jid)
+        if not target.short in self:
             #we have to create the chat win
             self[target.short] = self.createChat(target)
         return dict.__getitem__(self, target.short)