- Add test for incoming RAI message
- Only enable RAI if the user is affilated in MUC being left
- Handle error presence indicating a resouce-constraint
- Don't unregister stanza handlers in `leave`, since we still want to
  listen to RAI-related stanzas. Instead unregister upon the `destroy`
  event.

See: https://xmpp.org/extensions/xep-0333.html#rules-muc

- Send marker for last message before leaving and before subscribing to RAI
- clear cache of RAI-subscribed domains on reconnection

by not importing Strophe outside of @converse/headless

Mesage versions modal didn't open on subsequent clicks
Autocomplete: avoid undefined error

And remove it as a plugin.

As demanded by XEP-0393

And when nested, have no spaces between them.

Rename converse-core.js to core.js

Allows 3rd party plugins to add more buttons to the message actions dropdown

Set passed-in properties on modal