- other cleanup
- don't need compat.decimal, that approach never panned out. hopefully
outside libs aren't pulling it in, they shouldn't be

whereas the other do_rollback_twophase(), savepoint etc. work with
:class:`.Connection`.  the context on these are different as twophase/savepoint
are available at the :class:`.Connection` level, whereas commit/rollback are needed
at a lower level as well.  Rename the argument to "dbapi_connection" when the conneciton
is in fact the DBAPI interface.
- start thinking about being able to track "autocommit" vs. "commit", but not sure
we have a need for this yet.
- have Pool call out to a Dialect for all rollback/commit/close operations now.  Pool
no longer calls DBAPI methods directly.  May use this for a workaround for [ticket:2611]
- add a new Pool event reset() to allow the pool's reset of the connection to be intercepted.
- remove methods in Informix dialect which appear to be hardcoding some isolation
settings on new Transaction only; the isolation API should be implemented for Informix.
also removed "flag" for transaction commit/rollback being not available; this should
be based on server/DBAPI version and we will need someone with test access in order
to help determine how this should work

column_property(), relationship(), composite().
All MapperProperty classes have an auto-creating .info
dict available overall.

a disconnect detect + dispose that occurs
when the QueuePool has threads waiting
for connections would leave those
threads waiting for the duration of
the timeout on the old pool.   The fix
now notifies those waiters with a special
exception case and has them move onto
the new pool.  This fix may or may
not be ported to 0.7.  [ticket:2522]

usage of the event system; instance-level
collections are no longer created for a
particular type of event until
instance-level listeners are established
for that event.  [ticket:2516] Also in 0.7.9.

such as ``.. versionadded::``, ``.. versionchanged::`` and ``.. deprecated::``.