MUC: Add support for setting MUC room defaults from the config file Defaults are roughtly like this: muc_rooom_default_public = true muc_rooom_default_persistent = false muc_rooom_default_members_only = false muc_rooom_default_moderated = false muc_rooom_default_public_jids = false muc_rooom_default_change_subject = false muc_room_default_history_length = 20 muc_room_default_language = nil