CMFActivity: use message id in nofitication mail

dirty way of threading together retried activities

product/CMFActivity/ActivityTool.py

@@ -345,6 +345,8 @@ class Message(BaseMessage):
     path = '/'.join(self.object_path)
     mail_text = """From: %s <%s>
 To: %s
+Message-ID: <%s-%s@erp5-activity-failure>
+References: <%s-%s@erp5-activity-failure>
 Subject: %s: %s/%s
 
 Node: %s
@@ -355,7 +357,9 @@ Document: %s
 Method: %s
 Arguments: %r
 Named Parameters: %r
-""" % (email_from_name, activity_tool.email_from_address, user_email, message,
+""" % (email_from_name, activity_tool.email_from_address, user_email,
+       self.line.uid, self.method_id, self.line.uid, self.method_id,
+       message,
        path, self.method_id, activity_tool.getCurrentNode(), fail_count,
        self.user_name, self.line.uid, path, self.method_id, self.args, self.kw)
     if self.traceback: