XEP-0368 support

[hhartzer]

Is your feature request related to a problem? Please describe.

It would be nice to be able to connect without STARTTLS, so XEP-0368 support.

Describe the solution you'd like

Implement XEP-0368.

Describe alternatives you've considered

There isn't really an alternative. This can be useful for SNI proxying and some other features. It also seems slightly more secure than STARTTLS.

Thank you!

[sjaeckel]

That's something that must go into libstrophe, which already has basic support for the xmpp-client record, but not yet for xmpps-client.

You can force direct TLS of a connection by passing the tls legacy option when issuing the /connect command (or by editing the account via /account set <acc> tls legacy.