merge tip

diff --cc doc/build/mappers.rst
Simple merge

diff --cc lib/sqlalchemy/ext/declarative.py
Simple merge

diff --cc lib/sqlalchemy/orm/attributes.py
index 01f697edd644845c17ceb32f2d8094419d056d16,800f3889f7a6a7402718e0953c0fde8dc921708d..0ee06cca747a73e82a768a1e97c26af5ea43cef2
--- 1/lib/sqlalchemy/orm/attributes.py
--- 2/lib/sqlalchemy/orm/attributes.py
+++ b/lib/sqlalchemy/orm/attributes.py
@@@ -1439,8 -1465,9 +1448,9 @@@ def register_attribute_impl(class_, key
      manager[key].impl = impl
      
      manager.post_configure_attribute(key)
+ 
      
 -def register_descriptor(class_, key, proxy_property=None, comparator=None, 
 +def register_descriptor(class_, key, comparator=None, 
                                  parententity=None, property_=None, doc=None):
      manager = manager_of_class(class_)
  

diff --cc lib/sqlalchemy/orm/interfaces.py
Simple merge

diff --cc lib/sqlalchemy/orm/mapper.py
Simple merge

diff --cc lib/sqlalchemy/orm/properties.py
Simple merge

diff --cc lib/sqlalchemy/orm/query.py
Simple merge

diff --cc lib/sqlalchemy/orm/scoping.py
Simple merge