changes
1. introduced andes exchanges, queues and binding syncing
2. Revamped the Hazlecast coodination
3. Introduced AMQPContructs store to keep AMQP specific exchanges queues and bindings
4. Added method comments
5. Brought initialization of Andes kernel and shutting down to a new class and decoupled from Qpid
6. introduced queue listeners, binding listeners, exchange listeners and subscription listeners
7. introduced a common notification object as a bean for Hazelcast communication
Merge remote-tracking branch 'hasithaA/bindingAndExchangeModification' into Slots-RDBMS-Hazelcast-merge

Conflicts:
	modules/andes-core/broker/src/main/java/org/wso2/andes/amqp/QpidAMQPBridge.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/kernel/AndesContext.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/kernel/AndesContextStore.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/kernel/CassandraBasedAndesContextStore.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cassandra/AndesSubscriptionManager.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cassandra/QueueDeliveryWorker.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/ClusterManagementInformationMBean.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/ClusterManager.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/SubscriptionCoordinationManager.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/SubscriptionCoordinationManagerImpl.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/SubscriptionNotification.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/hazelcast/HazelcastAgent.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/hazelcast/QueueChangedListener.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/cluster/coordination/hazelcast/SubscriptionChangedListener.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/virtualhost/VirtualHostConfigSynchronizer.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/server/virtualhost/VirtualHostImpl.java
	modules/andes-core/broker/src/main/java/org/wso2/andes/subscription/SubscriptionStore.java
manual merge of changes done for queues bindings exchanges and subscription
models in andes by Hasitha Abeykoon