Add additional ha-policy parameters

[guidograzioli]

New parameters that apply to shared store or replication HA policies:

Variable	Description	Default
activemq_ha_allow_failback	Whether a server will automatically stop when another places a request to take over its place	true
activemq_ha_failover_on_shutdown	Will this backup server become active on a normal server shutdown	true
activemq_ha_restart_backup	Will this server, if a backup, restart once it has been stopped because of failback or scaling down	false
activemq_ha_check_for_active_server	Whether to check the cluster for a live server using our own server ID when starting up. This option is only necessary for performing 'fail-back' on replicating servers	false
activemq_ha_replication_cluster_name	Name of the cluster configuration to use for replication. This setting is only necessary in case you configure multiple cluster connections	""
activemq_ha_replication_group_name	With replication, if set, remote backup servers will only pair with primary servers with matching group-name	""

Fix #154