mod_rest: Add configuration of which stanzas to route to callback Makes it simpler to build APIs that only handle a certain kind of stanzas, letting them be handled by the unhandled stanza handler instead of having to write code to ignore certain kinds of stanzas.

---
summary: Allow server administrators to probe any user
...

This module lets server administrators send `<presence type="probe"/>`
to any local user and receive their presence in response, bypassing
roster checks.