Merge branch 'rel_0_9'

Conflicts:
	lib/sqlalchemy/dialects/postgresql/hstore.py
	lib/sqlalchemy/util/__init__.py
	lib/sqlalchemy/util/compat.py

1 files changed, 8 insertions, 7 deletions

diff --git a/lib/sqlalchemy/event.py b/lib/sqlalchemy/event.py
index f28f19ee9..d8c44dd05 100644
--- a/lib/sqlalchemy/event.py
+++ b/lib/sqlalchemy/event.py
@@ -171,7 +171,8 @@ class _EventMeta(type):
     associated _Dispatch classes."""
 
     def __init__(cls, classname, bases, dict_):
-        _create_dispatcher_class(cls, classname, bases, dict_)
+        if classname != 'MetaBase':
+            _create_dispatcher_class(cls, classname, bases, dict_)
         return type.__init__(cls, classname, bases, dict_)
 
 
@@ -200,12 +201,9 @@ def _remove_dispatcher(cls):
             if not _registrars[k]:
                 del _registrars[k]
 
-
-class Events(object):
+class Events(util.with_metaclass(_EventMeta, object)):
     """Define event listening functions for a particular target type."""
 
-    __metaclass__ = _EventMeta
-
     @classmethod
     def _accept_with(cls, target):
         # Mapper, ClassManager, Session override this to
@@ -377,9 +375,11 @@ class _EmptyListener(object):
     def __iter__(self):
         return iter(self.parent_listeners)
 
-    def __nonzero__(self):
+    def __bool__(self):
         return bool(self.parent_listeners)
 
+    __nonzero__ = __bool__
+
 
 class _CompoundListener(object):
     _exec_once = False
@@ -414,9 +414,10 @@ class _CompoundListener(object):
     def __iter__(self):
         return chain(self.parent_listeners, self.listeners)
 
-    def __nonzero__(self):
+    def __bool__(self):
         return bool(self.listeners or self.parent_listeners)
 
+    __nonzero__ = __bool__
 
 class _ListenerCollection(_CompoundListener):
     """Instance-level attributes on instances of :class:`._Dispatch`.