Using gnutls.c by default

[Lars Magne Ingebrigtsen]

I haven't seen any gnutls-related hangs in quite a while, so I tried by
trusty test case:

  (progn
   (require 'gnutls)
   (url-retrieve "https://www.google.no"; #'ignore)
   (url-retrieve "https://www.google.no"; #'ignore))

and it no longer hangs Emacs.

So I'm wondering whether `open-network-stream' should start using
gnutls.c by default now?  That would also give us greater test
coverage.

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/