Having an import of all contacts on each startup and after login is very
annoying, if you have a big list of contacts. If you choose to not join a
room with all contacts, you get the invitation over and over on each
restart of the service. Better is to have a command for the management
room to explicitly start the import.
* Fix user ID reservation in registration
* Fix some database things
* Add commands
* Add basic contact syncing and portal creation
* Add better error logging