Setup secondary ActiveMQ

A critical quality of the Bitmagasin system is the lack of single points of failures. This of course includes the central messaging bus, which therefore needs to have a secondary/backup instances, which can be used in case of a failure of the primary instance.

We therefore need to investigate how this work for ActiveMQ.

A major part of this task is to document the installation and failover/clustering configuration of the ActiveMQ instances.