Re: [PATCH] Prefer getenv("HOME") to find the UNIX home directory

I wrote:
> Meh. I guess there's not much point in arguing with facts on the
> ground. Anders' proposed behavior seems like the way to go then,
> at least so far as libpq is concerned.

So I pushed that, but while working on it I grew quite annoyed
at the messy API exhibited by src/port/thread.c, particularly
at how declaring its functions in port.h requires #including
<netdb.h> and <pwd.h> there. That means those headers are
read by every compile in our tree, though only a tiny number
of modules actually need either. So here are a couple of
follow-on patches to improve that situation.

For pqGethostbyname, there is no consumer other than
src/port/getaddrinfo.c, which makes it even sillier because that
file isn't even compiled on a large majority of platforms, making
pqGethostbyname dead code that we nonetheless build everywhere.
So 0001 attached just moves that function into getaddrinfo.c.

For pqGetpwuid, the best solution seemed to be to add a
less platform-dependent API layer, which I did in 0002
attached. Perhaps someone would object to the API details
I chose, but by and large this seems like an improvement
that reduces the amount of code duplication in the callers.

Thoughts?

regards, tom lane