on an index needed to have the same quoting for quoted names in
order to be recognized.  The fix makes the quotes optional but
also provides the old behavior for backwards compatibility with those
using the workaround.
fixes #3085

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.

type such as "charset" and "collation".  While MySQL wants all character-
based CAST calls to use the CHAR type, we now create a real CHAR
object at CAST time and copy over all the parameters it has, so that
an expression like ``cast(x, mysql.TEXT(charset='utf8'))`` will
render ``CAST(t.col AS CHAR CHARACTER SET utf8)``.

- Added new "unicode returns" detection to the MySQL dialect and
to the default dialect system overall, such that any dialect
can add extra "tests" to the on-first-connect "does this DBAPI
return unicode directly?" detection. In this case, we are
adding a check specifically against the "utf8" encoding with
an explicit "utf8_bin" collation type (after checking that
this collation is available) to test for some buggy unicode
behavior observed with MySQLdb version 1.2.3.  While MySQLdb
has resolved this issue as of 1.2.4, the check here should
guard against regressions.  The change also allows the "unicode"
checks to log in the engine logs, which was not previously
the case. [ticket:2906]

- move out tests, dialect specific out of compiler, compiler tests use new API,
legacy API tests in test_selecatble
- add support for adaptation of ForUpdateArg, alias support in compilers

of :class:`.ForeignKeyConstraint` is silently ignored on the MySQL
backend, will be reverted as of 0.9; this keyword will now render again, raising
errors on MySQL as it is not understood - the same behavior will also
apply to the ``initially`` keyword.  In 0.8, the keywords will remain
ignored but a warning is emitted.   Additionally, the ``match`` keyword
now raises a :class:`.CompileError` on 0.9 and emits a warning on 0.8;
this keyword is not only silently ignored by MySQL but also breaks
the ON UPDATE/ON DELETE options.

To use a :class:`.ForeignKeyConstraint`
that does not render or renders differently on MySQL, use a custom
compilation option.  An example of this usage has been added to the
documentation, see :ref:`mysql_foreign_keys`.
[ticket:2721] [ticket:2839]

mssql to ensure that any literal SQL expression values are
rendered directly as literals, instead of as bound parameters,
within a CREATE INDEX statement. [ticket:2742]
- don't need expression_as_ddl(); literal_binds and include_table
take care of this functionality.