a column setup on the ABC base which had a different attribute
name vs. column name would not be correctly mapped on the final
base class.   The failure on 0.9 would be silent whereas on
1.0 it raised an ArgumentError, so may not have been noticed
prior to 1.0.
fixes #3480

Fix camelize_classname and pluralize_collection functions as they didn't work as expected.

- alter the approach so that the initial callable is working just like add_criteria/with_criteria

When making baked query in classmethod of declarative base,
cls should be added in cache key.

    @as_declarative
    class Base(object):

        @classmethod
        def baked_query(cls):
            return bakery(lambda: session.query(cls), (cls,))

as a result of the bugfix for :ticket:`3167`,
where attribute and validation events are no longer
called within the flush process.  The mutable
extension was relying upon this behavior in the case where a column
level Python-side default were responsible for generating the new value
on INSERT or UPDATE, or when a value were fetched from the RETURNING
clause for "eager defaults" mode.  The new value would not be subject
to any event when populated and the mutable extension could not
establish proper coercion or history listening.  A new event
:meth:`.InstanceEvents.refresh_flush` is added which the mutable
extension now makes use of for this use case.
fixes #3427
- Added new event :meth:`.InstanceEvents.refresh_flush`, invoked
when an INSERT or UPDATE level default value fetched via RETURNING
or Python-side default is invoked within the flush process.  This
is to provide a hook that is no longer present as a result of
:ticket:`3167`, where attribute and validation events are no longer
called within the flush process.
- Added a new semi-public method to :class:`.MutableBase`
:meth:`.MutableBase._get_listen_keys`.  Overriding this method
is needed in the case where a :class:`.MutableBase` subclass needs
events to propagate for attribute keys other than the key to which
the mutable type is associated with, when intercepting the
:meth:`.InstanceEvents.refresh` or
:meth:`.InstanceEvents.refresh_flush` events.  The current example of
this is composites using :class:`.MutableComposite`.

off again so that test fixtures setup/teardown instrumentation as
expected
- clean up test_extendedattr.py and fix it to no longer leak
itself outside by ensuring _reinstall_default_lookups is always called,
part of #3408
- Fixed bug where when using extended attribute instrumentation system,
the correct exception would not be raised when :func:`.class_mapper`
were called with an invalid input that also happened to not
be weak referencable, such as an integer.
fixes #3408

refers to the table having a primary key.  fixes #3398