mod_privilege: process entity IQs (credit to adx) and messages with a constructed entity session

mod_http_muc_log: Use stanza:find to save a few bytes Why don't we have a stanza:get_child_attr(name, namespace, attrname) ?

mod_http_muc_log: Use XEP-0421 ID over nickname for XEP-0308 This prevents someone else from joining with the same nickname as someone who left, and "correcting" their messages.

mod_http_muc_log: Use XEP-0359 ID if available Clients apparently prefer this over message@id for reasons. Only used internally to find items for message edits

mod_http_muc_log: Rename variable for improved clarity

mod_http_muc_log: Remove dead code This might be something left over since a different variant where the loop went like `for n = i-1, i-100, -1 do ... end` i.e. it went trough a fixed number of items instead of all the page until the current message. Then it would have needed something to stop going over the end, but since the checks are simple it shouldn't be much of a problem looping over even a very busy day.

mod_rest: Fill in 'type' field in error registry The 'type' defaults to "modify" in util.error, which doesn't quite fit many of these error conditions. LuaFormatter changed ',' to ';'

mod_http_muc_log: Link to replied-to message using XEP-0461: Message Replies

mod_http_muc_log: Mention relevant XEPs in comments

mod_rest: Add JSON mapping for XEP-0461: Message Replies