One can use this to emit statements, which can not be
executed within a transaction (e. g. CREATE DATABASE):

    from sqlalchemy import create_engine

    eng = create_engine('postgresql://test:test@localhost/test')

    conn = eng.connect().execution_options(isolation_level='AUTOCOMMIT')
    conn.execute('CREATE DATABASE test2;')

Fixes issue #2072.

would produce a parenthesized expression not accepted by some databases.
[ticket:2754]

the :func:`.aliased` function.  Previously, composite attributes
wouldn't work correctly in comparison operations when aliasing
was applied.  Also in 0.8.2. [ticket:2755]

- version (0.9 for now)
- changelog
- move the test into the test suite so that all dialects can take advantage of it

Add basic support of unique constraints reflection

Inspection API already supports reflection of table
indexes information and those also include unique
constraints (at least for PostgreSQL and MySQL).
But it could be actually useful to distinguish between
indexes and plain unique constraints (though both are
implemented in the same way internally in RDBMS).

This change adds a new method to Inspection API - get_unique_constraints()
and implements it for SQLite, PostgreSQL and MySQL dialects.

"commit-on-return".  This is enabled with the rest of pool
"debug" logging.
[ticket:2752]