Fixed bug in new CTE feature for update/insert/delete whereby
an anoymous (e.g. no name passed) :class:`.CTE` construct around
the statement would fail.  The Alias base class of CTE checks
for the "named_with_column" attribute in order to detect if
the underlying selectable has a name; UpdateBase now provides
this as False.

Change-Id: I4b0309db21379a4c0cb93085298c86da3cf840e4
Fixes: #3744

Fixes: #3529
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: Ie3bf6ad70d9be9f0e44938830e922db03573991a
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/258

INSERT, UPDATE, and DELETE statements to both specify their own
WITH clause, as well as for these statements themselves to be
CTE expressions when they include a RETURNING clause.
fixes #2551

statement.  This feature is available by passing the
:paramref:`~.sqlalchemy.sql.expression.update.preserve_parameter_order`
flag either to the core :class:`.Update` construct or alternatively
adding it to the :paramref:`.Query.update.update_args` dictionary at
the ORM-level, also passing the parameters themselves as a list of 2-tuples.
Thanks to Gorka Eguileor for implementation and tests.
adapted from pullreq github:200

"multiple parameter sets" there is a much more common case
which works equally well for INSERT/UPDATE/DELETE e.g.
executemany().   reference #3476

for an insert from select are the string names, and not
the Column objects.  The MSSQL dialect in particular relies upon
checking for these keys in params to know if identity insert
should be on.  references #3360