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
Corrected the code Cassandra consistency levels
moved lock string to where lock is used
Merge pull request #198 from madhawa30/featue_cassandra_consistency

Corrected the code Cassandra consistency levels
Merge pull request #199 from sajinidesilva/queue_delete

Slot manager intellij idea warnings corrected