* net/nsm.el (nsm-format-certificate): Don't bug out on missing
elements.
(nsm-warnings-ok-p): The new version of this function always
returned nil when everything was OK.
* processes.texi (Network): Mention the new :warn-unless-encrypted
parameter to `open-network-stream'.
(Network): Mention the Network Security Manager.
* net/nsm.el: New file that implements a Network Security Manager.
* net/network-stream.el (open-network-stream): Add a new
:warn-unless-encrypted parameter.
(network-stream-open-plain): Allow warning unless encrypted.
(network-stream-open-starttls): Call the Network Security Manager.
(network-stream-open-tls): Ditto.