if a :class:`.Index` were associated with a :class:`.Column` that
is associated with a lower-case-t :class:`.TableClause`; the
association should be ignored for the purposes of associating
the index with a :class:`.Table`.
fixes #3616

such that we no longer assume the "ALGORITHM" keyword is present in
the reflected view source, as some users have reported this not being
present in some Amazon RDS environments.
fixes #3613

where the "default" argument was not included.
fixes #3605

for setting up baked lazy loaders would interfere with other
loader strategies that rely on lazy loading as a fallback, e.g.
joined and subquery eager loaders, leading to ``IndexError``
exceptions at mapper configuration time.
fixes #3612

the check added for a polymorphic joinedload from a
poly_subclass->class->poly_baseclass connection would fail for the
scenario of class->poly_subclass->class.
fixes #3611

would not bump a version id counter when in use.  The experience
here is still a little rough as the original version id is required
in the given dictionaries and there's not clean error reporting
on that yet.
fixes #3610

insert-default holding columns not otherwise included in the SET
clause (such as primary key cols) to get rendered into the RETURNING
even though this is an UPDATE.

- Major fixes to the :paramref:`.Mapper.eager_defaults` flag, this
flag would not be honored correctly in the case that multiple
UPDATE statements were to be emitted, either as part of a flush
or a bulk update operation.  Additionally, RETURNING
would be emitted unnecessarily within update statements.

fixes #3609