Performance improvement for redis-storage

Because the average time a nonce stays in Redis is 5hrs, during high load there could be over 300k nonce messages in Redis.  This is a problem when getAssociation is called without a handle this does an O(n) lookup for associations, leading to Redis slowing down.  


There are two purposes of this pr.
1) to be able to push the associations to a different database which does not have nonce messages.  
2) to be able to set a reasonable nonce timeout.