Re: Support for NSS as a libpq TLS backend

Attached is a rebased version which incorporates your recent patchset for
resource handling, as well as the connect_ok test patch.

I've implemented tracking the close_notify alert that you mentioned offlist,
but it turns out that the alert callbacks in NSS are of limited use so it
close_notify is currently the only checked description.  The enum which labels
the descriptions in the SSLAlert struct is private, so it's just sending over
an anonymous number apart from close_notify which is zero.

A few other fixups are included as well, like adapting the pending data read
function in the frontend to how the OpenSSL implementation does it.

--
Daniel Gustafsson        https://vmware.com/