at the connection and cursor levels. This handler will be called for each
variable being defined with the parameters cursor, name, defaultType, size,
precision and scale and expects to have a variable of the correct type
returned or None to indicate that default processing should take place.
NATIVE_FLOAT to allow specification of a variable of that specific type where
desired. Thanks to D.R. Boxhoorn for pointing out the fact that this was not
working properly when the arraysize was anything other than 1.
