to support dialect-level reflection options for all :class:`.Table`
objects reflected.

- Added a new dialect-level argument ``postgresql_ignore_search_path``;
this argument is accepted by both the :class:`.Table` constructor
as well as by the :meth:`.MetaData.reflect` method.  When in use
against Postgresql, a foreign-key referenced table which specifies
a remote schema name will retain that schema name even if the name
is present in the ``search_path``; the default behavior since 0.7.3
has been that schemas present in ``search_path`` would not be copied
to reflected :class:`.ForeignKey` objects.  The documentation has been
updated to describe in detail the behavior of the ``pg_get_constraintdef()``
function and how the ``postgresql_ignore_search_path`` feature essentially
determines if we will honor the schema qualification reported by
this function or not. [ticket:2922]

would lead to ``TypeError`` when compared to non-tuple types as it attempted
to apply tuple() to the "other" object unconditionally.  The
full range of Python comparison operators have now been implemented on
:class:`.RowProxy`, using an approach that guarantees a comparison
system that is equivalent to that of a tuple, and the "other" object
is only coerced if it's an instance of RowProxy. [ticket:2924]

and modernize the engines chapter a bit

MySQL, to correctly render the SET clause among multiple columns
with the same name across tables.  This also changes the name used for
the bound parameter in the SET clause to "<tablename>_<colname>" for
the non-primary table only; as this parameter is typically specified
using the :class:`.Column` object directly this should not have an
impact on applications.   The fix takes effect for both
:meth:`.Table.update` as well as :meth:`.Query.update` in the ORM.
[ticket:2912]

sent to the primary key constraint; existing tests in the PG dialect
confirm this.

reflection now updates the PKC in place.
- support the use case of the empty PrimaryKeyConstraint in order to specify
constraint options; the columns marked as primary_key=True will now be gathered
into the columns collection, rather than being ignored. [ticket:2910]
- add validation such that column specification should only take place
in the PrimaryKeyConstraint directly, or by using primary_key=True flags;
if both are present, they have to match exactly, otherwise the condition is
assumed to be ambiguous, and a warning is emitted; the old behavior of
using the PKC columns only is maintained.

- test_autoincrement_col still needs reflection overall

- clean up some shenanigans in reflection

arguments; [ticket:2866]
- add dialect specific kwarg functionality to ForeignKeyConstraint, ForeignKey