[patch] fe-connect.c doesn't handle EINTR correctly

Last year we had a drawn out discussion about this and I created a patch
for it. I never noticed that the patch didn't go in until I installed
7.2 the other day and realised that fe-connect.c never was fixed.

Here is the patch again. It is against CVS 3/16/2002. This time I only
rewrote the connect procedure at line 912, I leave it up to the regular
hackers to copy it's functionality to the SSL procedure just below it.

In summary, if a software writer implements timer events or other events
which generate a signal with a timing fast enough to occur while libpq
is inside connect(), then connect returns -EINTR. The code following
the connect call does not handle this and generates an error message.
The sum result is that the pg_connect() fails. If the timer or other
event is right on the window of the connect() completion time, the
pg_connect() may appear to work sporadically. If the event is too slow,
pg_connect() will appear to always work and if the event is too fast,
pg_connect() will always fail.

David