mod_vcard_muc: Add an alternative method of signaling avatar change When the avatar has been changed, a signal is sent that the room configuration has changed. Clients then do a disco#info query to find the SHA-1 of the new avatar. They can then fetch it as before, or not if they have it cached already. This is meant to be less disruptive than signaling via presence, which caused problems for some clients. If clients transition to the new method, the old one can eventually be removed. The namespace is made up while waiting for standardization. Otherwise it is very close to what's described in https://xmpp.org/extensions/inbox/muc-avatars.html

--
-- A module to indicate if a MUC message qualifies as historic based on XEP-0334 hints
--

module:depends"muc_mam"

module:log("debug", "Module loaded");

module:hook("muc-message-is-historic", function (event)
  if (event.stanza:get_child("no-store", "urn:xmpp:hints") or
    event.stanza:get_child("no-permanent-store", "urn:xmpp:hints")) then
      module:log("debug", "Not archiving stanza: %s (urn:xmpp:hints)", event.stanza)
    return false
  elseif event.stanza:get_child("store", "urn:xmpp:hints") then
    return true
  else
    return nil
  end
end)