"auto increment" column has been changed, such that autoincrement
is no longer implicitly enabled for a :class:`.Table` that has a
composite primary key.  In order to accommodate being able to enable
autoincrement for a composite PK member column while at the same time
maintaining SQLAlchemy's long standing behavior of enabling
implicit autoincrement for a single integer primary key, a third
state has been added to the :paramref:`.Column.autoincrement` parameter
``"auto"``, which is now the default. fixes #3216
- The MySQL dialect no longer generates an extra "KEY" directive when
generating CREATE TABLE DDL for a table using InnoDB with a
composite primary key with AUTO_INCREMENT on a column that isn't the
first column;  to overcome InnoDB's limitation here, the PRIMARY KEY
constraint is now generated with the AUTO_INCREMENT column placed
first in the list of columns.

may be called against a stale connection without the "connect"
event handler having been called, in the case where the pool
attempted to reconnect after being invalidated and failed; the stale
connection would remain present and would be used on a subsequent
attempt.  This issue has a greater impact in the 1.0 series subsequent
to 1.0.2, as it also delivers a blanked-out ``.info`` dictionary to
the event handler; prior to 1.0.2 the ``.info`` dictionary is still
the previous one.
fixes #3497

test as we implemented that as a separate test.

"max_row_buffer" execution option for BufferedRowResultProxy
- also add documentation, changelog and version notes
- rework the max_row_buffer argument to be interpreted from
the execution options upfront when the BufferedRowResultProxy
is first initialized.

Called after the :meth:`.Engine.dispose` method is called.

:func:`.engine_from_config` were not being parsed correctly;
these included ``pool_threadlocal`` and the psycopg2 argument
``use_native_unicode``. fixes #3435
- add legacy_schema_aliasing config parsing for mssql
- move use_native_unicode config arg to the psycopg2 dialect

the URL design a little simpler

and the database can no longer be connected towards, that the checkout
handler failure is caught, the attempt to re-acquire the connection
also raises an exception, but the underlying connection record
is not immediately re-checked in before the exception is propagated
outwards, having the effect that the checked-out record does not close
itself until the stack trace it's associated with is garbage collected,
preventing that record from being used for a new checkout until we
leave the scope of the stack trace.   This can lead to confusion
in the specific case of when the number of current stack traces
in memory exceeds the number of connections the pool can return,
as the pool will instead begin to raise errors about no more checkouts
available, rather than attempting a connection again.   The fix
applies a checkin of the record before re-raising.
fixes #3419

using descriptors; ensure that mock.patch() honors descriptor setters

old / new style, direct access, and ad-hoc patching and
unpatching as possible