[development] update.php and postgres 7.4

update.php from D5 to head doesn't work on pg7.4 - because you can't add constraints or default in the same statement as column add. Sure, it can be patched (and i've got one i'll submit) but how does the project fee about dropping old 7.4 and requiring pg8.0? If not for D6 then at least D7. It's an easy upgrade path, and 8 is in most distros (i dunno about redhat)