Fix event handlers should be called back by installed order

sphinx/events.py

@@ -12,7 +12,7 @@
 """
 from __future__ import print_function
 
-from collections import defaultdict
+from collections import OrderedDict, defaultdict
 
 from six import itervalues
 
@@ -47,7 +47,7 @@ class EventManager(object):
     def __init__(self):
         # type: () -> None
         self.events = core_events.copy()
-        self.listeners = defaultdict(dict)  # type: Dict[unicode, Dict[int, Callable]]
+        self.listeners = defaultdict(OrderedDict)  # type: Dict[unicode, Dict[int, Callable]]
         self.next_listener_id = 0
 
     def add(self, name):