and also that FB's cursor.rowcount is a little expensive, but not dramatically.
added a test to ensure cursor.rowcount is only called on update/delete.
the current default for firebird enable_rowcount is now True, leaving all the
options to turn it off etc..
by default, and can be re-enabled using the 'enable_rowcount'
flag with create_engine(), as well as the 'enable_rowcount'
execution context flag on a per-execute basis. This because
cursor.rowcount requires cursor access (can't be evaluated
lazily since the result auto-closes) and also incurs an
expensive round-trip.
Mike Bayer