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 blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```