emitted for the "_cursor_execute()" method of :class:`.Connection`;
this is the "quick" executor that is used for things like
when a sequence is executed ahead of an INSERT statement, as well as
for dialect startup checks like unicode returns, charset, etc.
the :meth:`.ConnectionEvents.before_cursor_execute` event was already
invoked here.  The "executemany" flag is now always set to False
here, as this event always corresponds to a single execution.
Previously the flag could be True if we were acting on behalf of
an executemany INSERT statement.

:func:`.attributes.flag_modified` where the change event would not be
propagated if the attribute had been reassigned to itself.
fixes #2997

against a non-selectable, such as a :func:`.literal_column`, and then
an attempt was made to use :meth:`.Query.join` such that the "left"
side would be determined as ``None`` and then fail.  This condition
is now detected explicitly.

flag for :func:`.event.listen` to work with mapper / instance events.

"true" / "false" or "1" / "0".
- added Boolean tests to the test suite

mark a constraint name as already having had a naming convention applied.
This token will be used by Alembic migrations as of Alembic 0.6.4
in order to render constraints in migration scripts with names marked
as already having been subject to a naming convention.
re: #2991

apply to :class:`.CheckConstraint` objects that are associated
directly with a :class:`.Column` instead of just on the
:class:`.Table`.

where the name of a check constraint making use of the
`"%(constraint_name)s"` token would get doubled up for the
constraint generated by a boolean or enum type, and overall
duplicate events would cause the `"%(constraint_name)s"` token
to keep compounding itself.
fixes #2991

or :meth:`.MapperEvents.after_configured` events are applied to a
specific mapper or mapped class, as the events are only invoked
for the :class:`.Mapper` target at the general level.