may be called against a stale connection without the "connect"
event handler having been called, in the case where the pool
attempted to reconnect after being invalidated and failed; the stale
connection would remain present and would be used on a subsequent
attempt.  This issue has a greater impact in the 1.0 series subsequent
to 1.0.2, as it also delivers a blanked-out ``.info`` dictionary to
the event handler; prior to 1.0.2 the ``.info`` dictionary is still
the previous one.
fixes #3497

(cherry picked from commit 4096ad0f0980f6940be57aaee85791df8f975cd7)

  to get all flake8 passing

renders "BETWEEN SYMMETRIC".  Also added a new negation operator
"notbetween_op", which now allows an expression like ``~col.between(x, y)``
to render as "col NOT BETWEEN x AND y", rather than a parentheiszed NOT
string.  fixes #2990