Description
Refactor the VirtualHost and MessageStore implementations ready to support the BDB HA (High Availability) Store:
https://cwiki.apache.org/confluence/display/qpid/Java+Broker+Design+-+HA+using+BDB
The principal change is to allow the store recovery phase to be executed many times during the lifetime of a virtual host. This is required for stores such as BDB HA where it is the store itself that decides when it becomes master.