core: added isJidInRoster method

src/core/xmpp.py

@@ -227,6 +227,10 @@ class SatRosterProtocol(xmppim.RosterClientProtocol):
     def getBareJids(self):
         """Return all bare jids (as unicode) of the roster"""
         return self._jids.keys()
+
+    def isJidInRoster(self, entity_jid):
+        """Return True if jid is in roster"""
+        return entity_jid.userhost() in self._jids
     
     def getItems(self):
         """Return all items of the roster"""