Merge pull request #190 from indikasampath2000/performance

Commenting on logic behind getMetaDataList method
refactored methods.
refactored enums related to cluster notifications.
updated licence header.
Merge pull request #191 from abeykoon/refactor_queue_delete

Refactor queue delete
Replace SequentialThreadPoolExecuter with DistruptorBasedFlusher
Merge pull request #192 from a5anka/disruptor_delivery_implementation

Replace SequentialThreadPoolExecuter with DistruptorBasedFlusher
Add cassandra consistency levels

Cassandra consistency levels for read write operations.
Only supports Cassandra below 1.2.x versions# Please enter the commit message for your changes. Lines starting
Fix Slot recovery bug in JDBC message stores

Reason for this was the CQL message store was returning results for
getNextNMessageMetadataFromQueue without  starting message while
JDBC message store returned with starting message.
Merge pull request #194 from a5anka/fix_slot_recovery

Fix Slot recovery bug in JDBC message stores
Moved methods in CassandraConstants class to GenericCQLDAO class
fixed subssubscribe to single durable topic subscriber and multiple.
fix a bug in binding sync. Sync  should not tell bridge again.
Cleaned the code
changed multiple subscription config.
Merge pull request #193 from madhawa30/featue_cassandra_consistency

Add cassandra consistency levels
Merge pull request #195 from abeykoon/unsubscribe_fixes

Unsubscribe fixes
minor change
Merge pull request #196 from ramith/master

minor change
slot manager idea warnings corrected