and :func:`.event.listens_for`.  This is a convenience feature which
will wrap the given listener such that it is only invoked once.

we will be able to parse dialect-specific arguments from string
configuration dictionaries.  Dialect classes can now provide their
own list of parameter types and string-conversion routines.
The feature is not yet used by the built-in dialects, however.
[ticket:2875]

of dbapi.Error (such as ``TypeError``, ``NotImplementedError``, etc.)
will propagate the exception unchanged.  Previously,
the error handling specific to the ``connect()`` routine would both
inappropriately run the exception through the dialect's
:meth:`.Dialect.is_disconnect` routine as well as wrap it in
a :class:`sqlalchemy.exc.DBAPIError`.  It is now propagated unchanged
in the same way as occurs within the execute process. [ticket:2881]
- add tests for this in test_parseconnect, but also add tests in test_execute
to ensure the execute() behavior as well

is recreated, due to a disconnect error.   This fixes a particular
issue in the Oracle 8 dialect, but in general the dialect.initialize()
phase should only be once per dialect.  Also in 0.8.3. [ticket:2776]

make sure that the DBAPI connection passed to the reset-on-return events/dialect hooks
is also a "fairy", so that dictionaries like "info" are available.  [ticket:2770]
- rework the execution_options system so that the dialect is given the job of making
any immediate adjustments based on a set event.  move the "isolation level" logic to use
this new system.   Also work things out so that even engine-level execution options
can be used for things like isolation level; the dialect attaches a connect-event
handler in this case to handle the task.
- to support this new system as well as further extensibiltiy of execution options
add events engine_connect(), set_connection_execution_options(), set_engine_execution_options()

- went through examples/ and cleaned out excess list() calls