Fixed typo in Changelog

Changelog

@@ -352,7 +352,7 @@ News
 * celeryd: Added ``CELERYD_MAX_TASKS_PER_CHILD`` /
   :option:`--maxtasksperchild`
 
-    Defineds the maximum number of tasks a pool worker can process before
+    Defines the maximum number of tasks a pool worker can process before
     the process is terminated and replaced by a new one.
 
 * Revoked tasks now marked with state ``REVOKED``, and ``result.get()``

celery/events/state.py

@@ -8,7 +8,8 @@ from celery import states
 HEARTBEAT_EXPIRE = 150 # 2 minutes, 30 seconds
 
 
-class Thing(object):
+class Element(object):
+    """Base class for types."""
     visited = False
 
     def __init__(self, **fields):
@@ -20,7 +21,8 @@ class Thing(object):
 
 
 
-class Worker(Thing):
+class Worker(Element):
+    """Worker State."""
 
     def __init__(self, **fields):
         super(Worker, self).__init__(**fields)
@@ -45,7 +47,8 @@ class Worker(Thing):
                 time.time() < self.heartbeats[0] + HEARTBEAT_EXPIRE)
 
 
-class Task(Thing):
+class Task(Element):
+    """Task State."""
     _info_fields = ("args", "kwargs", "retries",
                     "result", "eta", "runtime",
                     "exception")