Fixed bug whereby the ``__getstate__`` / ``__setstate__``
methods for sqlalchemy.util.Properties were
non-working due to the transition in the 1.0 series to ``__slots__``.
The issue potentially impacted some third-party applications.
Pull request courtesy Pieter Mulder.

Fixes: #3728
Change-Id: I01ebd425bbfe145747fea2edd0d2d412c74fd84d
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/286
(cherry picked from commit cab57e9bab04fbdea44690c08dff379a29eaab32)

would be turned into a list of individual characters.  This would
impact among other things using the :meth:`.Query.get` method
on a primary key that's a bytes object.
fixes #3660

the warning here to all safe_reraise() cases in Python 2.
- Revisiting :ticket:`2696`, first released in 1.0.10, which attempts to
work around Python 2's lack of exception context reporting by emitting
a warning for an exception that was interrupted by a second exception
when attempting to roll back the already-failed transaction; this
issue continues to occur for MySQL backends in conjunction with a
savepoint that gets unexpectedly lost, which then causes a
"no such savepoint" error when the rollback is attempted, obscuring
what the original condition was.

The approach has been generalized to the Core "safe
reraise" function which takes place across the ORM and Core in any
place that a transaction is being rolled back in response to an error
which occurred trying to commit, including the context managers
provided by :class:`.Session` and :class:`.Connection`, and taking
place for operations such as a failure on "RELEASE SAVEPOINT".
Previously, the fix was only in place for a specific path within
the ORM flush/commit process; it now takes place for all transational
context managers as well.
fixes #2696

the exception to itself as the "cause"; while the Python 3 interpreter
is OK with this, it could cause endless loops in iPython.
fixes #3625
- add tests for reraise, raise_from_cause
- raise_from_cause is the same on py2k/3k, use just one function

The error message changed to:

`'<' not supported between instances of 'foo' and 'bar'`

function; the caller still passes in the "wrapper"
- move tests for wrap_callable() to be generic util tests
- changelog for pullreq github:204

The places inspect.getargspec was being used were causing problems for
newer Python versions.