[stream-refactor] fix Py2.4 failure by implementing missing Timer method

mitogen/parent.py

@@ -508,12 +508,18 @@ class Timer(object):
         self.when = when
         self.func = func
 
+    def __repr__(self):
+        return 'Timer(%r, %r)' % (self.when, self.func)
+
     def __eq__(self, other):
         return self.when == other.when
 
     def __lt__(self, other):
         return self.when < other.when
 
+    def __le__(self, other):
+        return self.when <= other.when
+
     def cancel(self):
         """
         Cancel this event. If it has not yet executed, it will not execute