Add MessageCounterKey for the message stats capture.
Add message stats counter functionality to andes.
Changes to Hazelcast code
Merge pull request #37 from sperera/master

Changes to Hazelcast code
Optimize message status change data retrieval.
Optimize message status change data retrieval.
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
Initial implementation before taking messagestore modifications
removing global queues and addling slots instead- implemented basic functionalities
merged SlotDeliveryWorker and QueueDEliveryWorker
Initial work on H2BasedMessageStore
Updates done to the MessageStore Interface
Updates message id to be queried from DB as a long value.
H2 inmemory datastore updates.
Method updates in MessageStore
H2 in-memory message store functionality added.
H2 in-memory message store unit test added.
H2 messagestore unit testing related dependencies updated in pom.xml
DB connection object is used in method scope. Datasource object does the
connection pooling.

Relevant unit tests updated for H2 in-memory message store
.db files ignored
enabled multiple slots to be taken from one node for one queue
MessageStore Implementation to use for MB is now read from config file at
startup.
remove use of some deprecated MessageStore functions