plugins/muc/mod_muc: Move Xep-0307 MUC unique to seperate file
plugins/muc/muc.lib: Split out `send_history` into `parse_history` and `get_history`
plugins/muc/muc.lib: Split up `handle_to_room` into smaller handlers (thanks sysko)
plugins/muc/muc.lib: Factor `handle_to_occupant` out into many functions
plugins/muc/muc.lib: Split out the room iq handler into functions
plugins/muc/muc.lib: Refactor _to_occupant handlers
plugins/muc/muc.lib: Move (de)construct_stanza_id into `handle_iq_to_occupant`

It is the only place they were used; and I left the old function names in as comments.
One reason for doing this was to reduce accesses to _occupants; which may be in a database in future revisions
plugins/muc/muc.lib: Add some missing return values
plugins/muc/muc.lib: Make use of return values to send service-unavailable errors
plugins/muc/muc.lib: Move all kick code into one place
plugins/muc/muc.lib: Add disco iq handlers with compatible argument signature
plugins/muc/muc: Add copyright for daurnimator
plugins/muc/muc: Check for mediated invites in a smarter way
plugins/muc/muc: Rename `handle_invite_to_room` to `handle_mediated_invite`; clean up logic
plugins/muc/muc: Support mediated declines
plugins/muc/muc: When there's no history; return an empty iterator
plugins/muc/muc: Only call get_password once in invite creation
plugins/muc/muc: Add 'muc-occupant-left' event
plugins/muc/mod_muc: Refactor to use new methods available
plugins/muc/mod_muc: host sessions have a .send these days