The "Bound field" property of a list box control, specifying which
column of the list boxes result set should be used for data exchange,
can have the value "0" now.
Given that the value was always 0-based (i.e. "1" refers to the second
column in the result set), the former minimum value "1" implied that
the list result set must have at least two columns for the list box to
be of use.
There was no real reason for this limitation to not allow "0" (except
some stone-aged implementation quirks, which have been exorcised), so
it has been removed.