* server list for each agent, primary server and (N-1) ordered backups
rev1148 - entities, dbsetup/dbsetup scripts for high-availability infrastructure; might need tiny tweaks to the model here and there in the future, but we can consider this closed for now as 98%+ of the work is now complete.
rev1172 - add secure port to Server entity and dbsetup/dbupgrade scripts;
rev1176 - add secure port for Server entity to RHQ_SERVER table not RHQ_AGENT table;
rev1208 - agent status field need not be required, but set the default to zero;
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-670