mod_sasl2: Further break up success handling, into pre/post stream:features This allows us to enable mod_smacks after sending success, but before sending stream:features. Previously, the features were being calculated before SM was finalized on the session. We can't finalize SM before sending <success> because it may generate stanzas.

---
summary: STARTTLS failure test
---

This module responds to `<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>` with
`<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>`, in order to test
how clients and server behave.

See [RFC6120 Section 5.4.2.2](https://xmpp.org/rfcs/rfc6120.html#rfc.section.5.4.2.2)