BUG #1467: fe_connect doesn't handle EINTR right

Attached is a patch which corrects the behavior. I verified that the
patch does not interfere with normal operation (using psql) but
unfortunately the code path is virtually impossible to test without a
really slow connection to a postgresql server [which I thankfully
don't have]. To test the patch, you would need to send an interrupt
at the exact time that the kernel is connect()ing in blocking mode-
good luck.

Also, I recommend removing a (sarcastic?) comment left by a previous
developer- I wrote a note about in my patch.

The patch is against 8.0.3 [because HEAD requires access to a
specific version of bison] but I imagine that the code hasn't changed
in fe-connect.c since then.

Patch against src/interfaces/libpq/fe-connect.c (v 8.0.3)