parameters are now available on the :meth:`.MetaData.reflect`
method.
- starting to use paramref and need newer paramlinks version.

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

attempts when an existing connection attempt is blocking.  Previously,
the production of new connections was serialized within the block
that monitored overflow; the overflow counter is now altered within
it's own critical section outside of the connection process itself.
[ticket:2880]

connection to be available, such that for a connection pool
with no timeout specified, it will every half a second break out of
the wait to check for the so-called "abort" flag, which allows the
waiter to break out in case the whole connection pool was dumped;
normally the waiter should break out due to a notify_all() but it's
possible this notify_all() is missed in very slim cases.
This is an extension of logic first introduced in 0.8.0, and the
issue has only been observed occasionally in stress tests.

   "@", or "/" must be encoded." - so re-apply encoding to both password
and username, don't encode spaces as plus signs, don't encode any chars
outside of :, @, / on stringification - but we still parse for any
%XX character (is that right?)

:func:`.make_url` function **no longer URL encode the password**.
Database passwords that include characters like spaces, plus signs
and anything else should now represent these characters directly,
without any URL escaping. [ticket:2873]