- support __only_on__ and __backend__ at the same time
- break up the <authors> copyright comment as part of a pass
to get all flake8 passing
- fully flake8 test/aaa_profiling
- The :meth:`.TypeEngine.with_variant` method will now accept a
type class as an argument which is internally converted to an
instance, using the same convention long established by other
constructs such as :class:`.Column`. fixes #3122
imports gone bad
- mark tests failing for mysqlconnector, oursql
- determine the root cause of the mysqlconnector issue, report
it and move on
fixed style to conform to PEP8
Merge branch 'master' of https://github.com/celttechie/sqlalchemy

Pulling from new fork of SQLAlchemy
OK use tox
update test runners to be module-based
- Fixed bug in :class:`.Enum` and other :class:`.SchemaType`
subclasses where direct association of the type with a
:class:`.MetaData` would lead to a hang when events
(like create events) were emitted on the :class:`.MetaData`.
fixes #3124
PEP8 style fixes
Merge branch 'pep8'
- adjust this to work on PG also
- ensure usedevelop is present so that C exts are in the tests
PEP8 tidy for test/orm/test_versioning.py
Fix support for two phase commit in pg8000 dialect

The postgresql base dialect has problems with two-phase commit because
there isn't a standard way of handling autocommit in DBAPI. This commit
modifies the pg8000 dialect to use the DBAPI tpc extension, which is
supported by pg8000 as of version 1.9.11.
PEP8 tidy for test/orm/test_transaction.py
passing orm