From pg8000-1.9.14 sane_multi_rowcount is supported so this commit
updates the dialect accordingly.

events from firing for those statements which it uses internally
to detect if a table exists or not.   This is achieved using an
execution option ``skip_user_error_events`` that disables the handle
error event for the scope of that execution.   In this way, user code
that rewrites exceptions doesn't need to worry about the MySQL
dialect or other dialects that occasionally need to catch
SQLAlchemy specific exceptions.

array.__init__() expects a list as its sole parameter but inside _bind_param(), instead of sending a list it's sending each item in the list as a separate argument which is incorrect.

- add support for IDENTITY INSERT setting for INSERT with inline VALUES

where engine-level isolation level parameter would raise an error
on connect. fixes #3134

sqlalchemy/orm, sqlalchemy/event, sqlalchemy/testing

The postgresql base dialect has problems with two-phase commit because
there isn't a standard way of handling autocommit in DBAPI. This commit
modifies the pg8000 dialect to use the DBAPI tpc extension, which is
supported by pg8000 as of version 1.9.11.