Renames registered_tasks to registered for consistency

celery/task/control.py

@@ -65,7 +65,7 @@ class Inspect(object):
     def revoked(self):
         return self._request("dump_revoked")
 
-    def registered_tasks(self):
+    def registered(self):
         return self._request("dump_tasks")
 
     def enable_events(self):
@@ -89,6 +89,8 @@ class Inspect(object):
     def active_queues(self):
         return self._request("active_queues")
 
+    registered_tasks = registered
+
 
 class Control(object):
     Mailbox = Mailbox