with the psycopg2 dialect in conjunction with non-ascii values
and ``native_enum=False`` would fail to decode return results properly.
This stemmed from when the PG :class:`.postgresql.ENUM` type used
to be a standalone type without a "non native" option.
fixes #3354
- corrected the assertsql comparison rule to expect a non-ascii
SQL string

:ticket:`3184` would cause index operations to fail on Postgresql
versions 8.4 and earlier.  The enhancements are now
disabled when using an older version of Postgresql.
fixes #3343

out.
- add __backend__ to the dialect suite so that it runs on CI.
- will be 1.0.0b3

- changelog for #2771

DROP TYPE instruction when a plain ``table.drop()`` is called,
assuming the object is not associated directly with a
:class:`.MetaData` object.   In order to accomodate the use case of
an enumerated type shared between multiple tables, the type should
be associated directly with the :class:`.MetaData` object; in this
case the type will only be created at the metadata level, or if
created directly.  The rules for create/drop of
Postgresql enumerated types have been highly reworked in general.
fixes #3319