mod_delegation: update to XEP-0355 v0.5 - namespace bump to "urn:xmpp:delegation:2" - disco remaining infos now uses the XEP defined "urn:xmpp:delegation:2:bare:disco#info:*" namespace - complemeted disco remaining infos implementation for requests made on nodes not already managed by the server - bare JID disco items now uses the XEP defined "urn:xmpp:delegation:2:bare:disco#items:*'" namespace

This module adds a command to `prosodyctl` for listing users.

``` sh
prosodyctl mod_listusers
```