initdb detecting date order

Here's a patch for initdb detecting the date order of the lc_time locale
and initializing the datestyle parameter of the new cluster
accordingly.

This relies on feeding an umambiguous date through strftime("%x") and
checking in which order things come out. (This was suggested to me by
Martin Pitt a while ago.) I've tested this with a number of locales
and it seems to work. Does anyone see a problem with this?

(Documentation and perhaps an initdb progress notification line is of
course still missing.)

--
Peter Eisentraut
http://developer.postgresql.org/~petere/