Conflicts:
	doc/build/index.rst

_ConnectionRecord.checkin() so that this functionality is
encapsulated; is now called from two different locations
for [ticket:2772].
- Fixed bug where :class:`.QueuePool` would lose the correct
checked out count if an existing pooled connection failed to reconnect
after an invalidate or recycle event. [ticket:2772]

Preserve reset_on_return when recreating a Pool.

- 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.