plugin text commands: added /parrot and /unparrot commands to use Parrot plugin

- /parrot command add parrot link between the current entity/room and the entity given as an argument (must be a valid jid)
    - similarly, /unparrot remove the 2 links between those entities.
    - Parrot is a new dependency of text commands

src/core/xmpp.py

@@ -106,7 +106,7 @@ class SatMessageProtocol(xmppim.MessageProtocol):
 
     def onMessage(self, message):
         debug (_(u"got message from: %s"), message["from"])
-        if not self.host.trigger.point("MessageReceived",message, profile=self.parent.profile):
+        if not self.host.trigger.point("MessageReceived", message, profile=self.parent.profile):
             return
         for e in message.elements():
             if e.name == "body":