core: improved roster management + misc:

- updated methods to no use anymore methods deprecated in Wokkel
    - use of full jid when it make sense instead of bare jid
    - getContacts, updateContact and delContact are now asynchronous

src/stdui/ui_contact_list.py

@@ -50,7 +50,7 @@ class ContactList(object):
         @return: list[string]
         """
         client = self.host.getClient(profile)
-        ret = [contact.userhost() for contact in client.roster.getBareJids()]
+        ret = [contact.full() for contact in client.roster.getJids()]
         ret.sort()
         return ret