a few changes for py2k:

* map_imperatively() includes the check that a class
  is being sent, this was only working for mapper() before

* the test suite didn't place the py2k "autouse" workaround
  in the correct order, seemingly, tried to adjust the
  per-test ordering setup in pytestplugin.py

Change-Id: I4cc39630724e810953cfda7b2afdadc8b948e3c2

An extra layer of warning messages has been added to the functionality
of :meth:`_orm.Query.join` and the ORM version of
:meth:`_sql.Select.join`, where a few places where "automatic aliasing"
continues to occur will now be called out as a pattern to avoid, mostly
specific to the area of joined table inheritance where classes that share
common base tables are being joined together without using explicit aliases.
One case emits a legacy warning for a pattern that's not recommended,
the other case is fully deprecated.

The automatic aliasing within ORM join() which occurs for overlapping
mapped tables does not work consistently with all APIs such as
``contains_eager()``, and rather than continue to try to make these use
cases work everywhere, replacing with a more user-explicit pattern
is clearer, less prone to bugs and simplifies SQLAlchemy's internals
further.

The warnings include links to the errors.rst page where each pattern is
demonstrated along with the recommended pattern to fix.

* Improved the exception message generated when configuring a mapping with
  joined table inheritance where the two tables either have no foreign key
  relationships set up, or where they have multiple foreign key relationships
  set up. The message is now ORM specific and includes context that the
  :paramref:`_orm.Mapper.inherit_condition` parameter may be needed
  particularly for the ambiguous foreign keys case.

* Add explicit support in the _expect_warnings() assertion for nested
  _expect_warnings calls

* generalize the NoCache fixture, which we also need to catch warnings
  during compilation consistently

* generalize the __str__() method for the HasCode mixin so all warnings
  and errors include the code link in their string

Fixes: #6974
Change-Id: I84ed79ba2112c39eaab7973b6d6f46de7fa80842

Revised the means by which the
:attr:`_orm.ORMExecuteState.user_defined_options` accessor receives
:class:`_orm.UserDefinedOption` and related option objects from the
context, with particular emphasis on the "selectinload" on the loader
strategy where this previously was not working; other strategies did not
have this problem. The objects that are associated with the current query
being executed, and not that of a query being cached, are now propagated
unconditionally. This essentially separates them out from the "loader
strategy" options which are explicitly associated with the compiled state
of a query and need to be used in relation to the cached query.

The effect of this fix is that a user-defined option, such as those used
by the dogpile.caching example as well as for other recipes such as
defining a "shard id" for the horizontal sharing extension, will be
correctly propagated to eager and lazy loaders regardless of whether
a cached query was ultimately invoked.

Fixes: #6887
Change-Id: Ieaae5b01c85de26ea732ebd625e6e5823a470492

Also replace http://pypi.python.org/pypi with https://pypi.org/project

Change-Id: I84b5005c39969a82140706472989f2a30b0c7685

this test currently causes the test suite to hang; it previously
was not actually running the worker thread
as the testing_engine() fixture
was rejecting the "transfer_staticpool" keyword argument.

as we seem to have a greenlet-related segfault in 3.10.0b2 I am
going to have to get the greenlet devs to run the test suite
so i want to get anything not totally smooth out of it for the
moment.

Change-Id: Ib453d0bc23ca013598bc80ff29e5da496771d5b1

Applied consistent behavior to the use case of
calling ``.commit()`` or ``.rollback()`` inside of an existing
``.begin()`` context manager, with the addition of potentially
emitting SQL within the block subsequent to the commit or rollback.
This change continues upon the change first added in
:ticket:`6155` where the use case of calling "rollback" inside of
a ``.begin()`` contextmanager block was proposed:

* calling ``.commit()`` or ``.rollback()`` will now be allowed
without error or warning within all scopes, including
that of legacy and future :class:`_engine.Engine`, ORM
:class:`_orm.Session`, asyncio :class:`.AsyncEngine`.  Previously,
the :class:`_orm.Session` disallowed this.

* The remaining scope of the context manager is then closed;
when the block ends, a check is emitted to see if the transaction
was already ended, and if so the block returns without action.

* It will now raise **an error** if subsequent SQL of any kind
is emitted within the block, **after** ``.commit()`` or
``.rollback()`` is called.   The block should be closed as
the state of the executable object would otherwise be undefined
in this state.

Fixes: #6288
Change-Id: I8b21766ae430f0fa1ac5ef689f4c0fb19fc84336

Added support for the aiosqlite database driver for use with the
SQLAlchemy asyncio extension.

Fixes: #5920
Change-Id: Id11a320516a44e886a6f518d2866a0f992413e55

Fixed regression where the SQL compilation of a :class:`.Function` would
not work correctly if the object had been "annotated", which is an internal
memoization process used mostly by the ORM. In particular it could affect
ORM lazy loads which make greater use of this feature in 1.4.

Fixes: #6095
Change-Id: I7a6527df651f440a04d911ba78ee0b0dd4436dcd

The API for :meth:`_asyncio.AsyncSession.delete` is now an awaitable;
this method cascades along relationships which must be loaded in a
similar manner as the :meth:`_asyncio.AsyncSession.merge` method.

Fixes: #5998
Change-Id: Iae001efe99a1dcc47598b4a2491d17c4157fbbfa

Fixed issue where mixin attribute rules were not taking
effect correctly for attributes pulled from dataclasses
using the approach added in #5745.

Fixes: #5876
Change-Id: I45099a42de1d9611791e72250fe0edc69bed684c