That is, after exhausing all rows using the fetch methods, the
DBAPI cursor is released as before and the object may be safely
discarded, but the fetch methods may continue to be called for which
they will return an end-of-result object (None for fetchone, empty list
for fetchmany and fetchall).   Only if :meth:`.ResultProxy.close`
is called explicitly will these methods raise the "result is closed"
error.
fixes #3330 fixes #3329

consists mainly of adjusting fixtures to ensure connections are closed
explicitly.  psycopg2cffi also handles unicode bind parameter
names differently than psycopg2, and seems to possibly have a little less
control over floating point values at least in one test which is
marked as a "fail", though will see if it runs differently on linux
than osx..
- changelog for psycopg2cffi, fixes #3052

levels; :meth:`.Connection.get_isolation_level`,
:attr:`.Connection.default_isolation_level`.
- enhance documentation inter-linkage between new accessors,
existing isolation_level parameters, as well as in
the dialect-level methods which should be fully covered
by Engine/Connection level APIs now.

they don't really belong into a new suite in test_execute

and parameters are not displayed if None, reducing confusion for
error messages that weren't related to a statement.  The full
module and classname for the DBAPI-level exception is displayed,
making it clear that this is a wrapped DBAPI exception.  The
statement and parameters themselves are bounded within a bracketed
sections to better isolate them from the error message and from
each other.
fixes #3172

that union() can be called, in the case of a dialect that uses
execution options inside of initialize() (e.g. oursql)

:paramref:`.create_engine.execution_options` or
:meth:`.Engine.update_execution_options` are not passed to the
special :class:`.Connection` used to initialize the dialect
within the "first connect" event; dialects will usually
perform their own queries in this phase, and none of the
current available  options should be applied here.  In
particular, the "autocommit" option was causing an attempt to
autocommit within this initial connect which would fail with
an AttributeError due to the non-standard state of the
:class:`.Connection`.
fixes #3200

when you call :meth:`.Connection.connect`, would not share transaction
status with the parent.  The architecture of branching has been tweaked
a bit so that the branched connection defers to the parent for
all transactional status and operations.
fixes #3190