Implemented the SQLAlchemy 2 :func:`.future.create_engine` function which
is used for forwards compatibility with SQLAlchemy 2.   This engine
features always-transactional behavior with autobegin.

Allow execution options per statement execution.  This includes
that the before_execute() and after_execute() events now accept
an additional dictionary with these options, empty if not
passed; a legacy event decorator is added for backwards compatibility
which now also emits a deprecation warning.

Add some basic tests for execution, transactions, and
the new result object.   Build out on a new testing fixture
that swaps in the future engine completely to start with.

Change-Id: I70e7338bb3f0ce22d2f702537d94bb249bd9fb0a
Fixes: #4644

Change-Id: I08440dc25e40ea1ccea1778f6ee9e28a00808235

Replace inspect_getargspec with inspect_getfullargspec
including a compatibility fallback for Py2k and use
getfullargspec fully.

Change-Id: I92bce0aafc37ce1a360b4f61b75f5892d0911c7e

These changes should be ported from 1.3 back to 1.0 or
possibly 0.9 to the extent they are relevant in each
version. In 1.3 we hope to turn all deprecation documentation
into warnings.

Change-Id: I205186cde161af9389af513a425c62ce90dd54d8

Change-Id: I6a71f4924d046cf306961c58dffccf21e9c03911

This is a straight reformat run using black as is, with no edits
applied at all.

The black run will format code consistently, however in
some cases that are prevalent in SQLAlchemy code it produces
too-long lines.   The too-long lines will be resolved in the
following commit that will resolve all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.

Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9

Change-Id: I3ef36bfd0cb0ba62b3123c8cf92370a43156cf8f

Change-Id: I4e8c2aa8fe817bb2af8707410fa0201f938781de