distutils appropriately, and errors would be emitted at the end
of the test suite.

removal of the ``setuptools.Feature`` extension from setuptools.
If this keyword isn't present, the setup will still succeed
with setuptools rather than falling back to distutils.  C extension
building can be disabled now also by setting the
DISABLE_SQLALCHEMY_CEXT environment variable.  This variable works
whether or not setuptools is even available. fixes #2986
- using platform.python_implementation() in setup.py to detect CPython.
I've tested this function on OSX and linux on Python 2.6 through 3.4,
including 3.1, 3.2, 3.3.
Unfortunately, on OSX + 3.2 only, it seems to segfault.  I've tried
installing 3.2.5 from the python.org .dmg, building it from source,
and also blew away the whole 3.2 directory, something seems to be wrong
with the "platform" module on that platform only, and there's also no
issue on bugs.python.org; however, I'm going with
it anyway. If someone is using 3.2 on OSX they really should be upgrading.

is currently being supported in addition to nose, and will likely
be preferred to nose going forward.   The nose plugin system used
by SQLAlchemy has been split out so that it works under pytest as
well.  There are no plans to drop support for nose at the moment
and we hope that the test suite itself can continue to remain as
agnostic of testing platform as possible.  See the file
README.unittests.rst for updated information on running tests
with pytest.

The test plugin system has also been enhanced to support running
tests against mutiple database URLs at once, by specifying the ``--db``
and/or ``--dburi`` flags multiple times.  This does not run the entire test
suite for each database, but instead allows test cases that are specific
to certain backends make use of that backend as the test is run.
When using pytest as the test runner, the system will also run
specific test suites multiple times, once for each database, particularly
those tests within the "dialect suite".   The plan is that the enhanced
system will also be used by Alembic, and allow Alembic to run
migration operation tests against multiple backends in one run, including
third-party backends not included within Alembic itself.
Third party dialects and extensions are also encouraged to standardize
on SQLAlchemy's test suite as a basis; see the file README.dialects.rst
for background on building out from SQLAlchemy's test platform.

any supported CPython 2 or 3 environment. [ticket:2161]

actual mock objects from the mock library.  I'd like to use mock
for new tests so we might as well use it in obvious places.
- use unittest.mock in py3.3
- changelog
- add a note to README.unittests
- add tests_require in setup.py
- have tests import from sqlalchemy.testing.mock
- apply usage of mock to one of the event tests.  we can be using
this approach all over the place.