Restore empty string <-> int behaviour for 7.2

I've written a small patch that could be useful for people with old
applications, since it restores the original behaviour of silently treating
empty strings as 0 (at least for integers). It introduces a new bool GUC
variable "empty_equals_0" with default "off". With a simple "SET
empty_equals_0 to on" or via "ALTER DATABASE FOO ... SET empty_equals_0 to
on" the pre 7.3 behaviour can be restored again on a per database base.

I don't think such a patch is worthy for inclusion in postgresql, but as
external patch it's useful. What's the best place to submit such a patch?
gborg?

Thanks for the info!