* Add missing 'mix' tables and indexes
* Fix text vs varchar issues
Various tests triggered this error:
The data types text and varchar are incompatible in the equal to operator.
Caused by incompatible 'text' columns in muc_online_room,
muc_online_users, pubsub_node_option, and pubsub_node tables.
* Fix definition of mqtt_pub table
This table incorrectly included 'server_host' column in old schema, and
had other inconsistencies.
Stu Tomlinson
5e94fdcfd5